Dans cette thèse nous proposons de nouveaux algorithmes d'analyse vidéo. La première contribution de cette thèse concerne le domaine de la segmentation de vidéos avec pour objectif d'obtenir une segmentation dense et spatio-temporellement cohérente. Nous proposons de combiner les aspects spatiaux et temporels d'une vidéo en une seule notion, celle de Fibre. Une fibre est un ensemble de trajectoires qui sont spatialement connectées par un maillage. Les fibres sont construites en évaluant simultanément les aspects spatiaux et temporels. Par rapport a l’état de l'art une segmentation de vidéo a base de fibres présente comme avantages d’accéder naturellement au voisinage grâce au maillage et aux correspondances temporelles pour la plupart des pixels de la vidéo. De plus, cette segmentation à base de fibres a une complexité quasi linéaire par rapport au nombre de pixels. La deuxième contribution de cette thèse concerne le suivi d'objets multiples. Nous proposons une approche de suivi qui utilise des caractéristiques des points suivis, la cinématique des objets suivis et l'apparence globale des détections. L'unification de toutes ces caractéristiques est effectuée avec un champ conditionnel aléatoire. Ensuite ce modèle est optimisé en combinant les techniques de passage de message et une variante de processus ICM (Iterated Conditional Modes) pour inférer les trajectoires d'objet. Une troisième contribution mineure consiste dans le développement d'un descripteur pour la mise en correspondance d'apparences de personne. Toutes les approches proposées obtiennent des résultats compétitifs ou meilleurs (qualitativement et quantitativement) que l’état de l'art sur des base de données. / In this thesis we propose novel algorithms for video analysis. The first contribution of this thesis is in the domain of video segmentation wherein the objective is to obtain a dense and coherent spatio-temporal segmentation. We propose joining both spatial and temporal aspects of a video into a single notion Fiber. A fiber is a set of trajectories which are spatially connected by a mesh. Fibers are built by jointly assessing spatial and temporal aspects of the video. Compared to the state-of-the-art, a fiber based video segmentation presents advantages such as a natural spatio-temporal neighborhood accessor by a mesh, and temporal correspondences for most pixels in the video. Furthermore, this fiber-based segmentation is of quasi-linear complexity w.r.t. the number of pixels. The second contribution is in the realm of multiple object tracking. We proposed a tracking approach which utilizes cues from point tracks, kinematics of moving objects and global appearance of detections. Unification of all these cues is performed on a Conditional Random Field. Subsequently this model is optimized by a combination of message passing and an Iterated Conditional Modes (ICM) variant to infer object-trajectories. A third, minor, contribution relates to the development of suitable feature descriptor for appearance matching of persons. All of our proposed approaches achieve competitive and better results (both qualitatively and quantitatively) than state-of-the-art on open source datasets.

Cette thèse aborde la résolution des problèmes d'interaction fluide-structure par un algorithme consistant en un couplage entre deux solveurs : un pour le fluide et un pour la structure. Pour assurer la cohérence entre les maillages fluide et structure, on considère également une discrétisation de chaque domaine par volumes finis. En raison des difficultés de décomposition du domaine en sous-domaines, nous considérons pour chaque environnement un algorithme parallèle de multi-splitting (ou multi-décomposition) qui correspond à une présentation unifiée des méthodes de sous-domaines avec ou sans recouvrement. Cette méthode combine plusieurs applications de points fixes contractantes et nous montrons que, sous des hypothèses appropriées, chaque application de points fixes est contractante dans des espaces de dimensions finies normés par des normes hilbertiennes et non-hilbertiennes. De plus, nous montrons qu'une telle étude est valable pour les résolutions parallèles synchrones et plus généralement asynchrones de grands systèmes linéaires apparaissant lors de la discrétisation des problèmes d'interaction fluide-structure et peut être étendue au cas où le déplacement de la structure est soumis à des contraintes. Par ailleurs, nous pouvons également considérer l’analyse de la convergence de ces méthodes de multi-splitting parallèles asynchrones par des techniques d’ordre partiel, lié au principe du maximum discret, aussi bien dans le cadre linéaire que dans celui obtenu lorsque les déplacements de la structure sont soumis à des contraintes. Nous réalisons des simulations parallèles pour divers cas test fluide-structure sur différents clusters, en considérant des communications bloquantes et non bloquantes. Dans ce dernier cas nous avons eu à résoudre une difficulté d'implémentation dans la mesure où une erreur irrécupérable survenait lors de l'exécution ; cette difficulté a été levée par introduction d’une méthode assurant la terminaison de toutes les communications non bloquantes avant la mise à jour du maillage. Les performances des simulations parallèles sont présentées et analysées. Enfin, nous appliquons la méthodologie présentée précédemment à divers contextes d'interaction fluide-structure de type industriel sur des maillages non structurés, ce qui constitue une difficulté supplémentaire.

Title: Choosing the right marketing strategy on social media: A study on how restaurants affect consumer attitudes through different types of marketing on Instagram. Level: Final assignment for Bachelor Degrees in Business Administration Authors: Tim Prasertsri, Jakob Johnson Supervisor: Jonas Molin och Lars-Johan Åge Date: 2018 - 05 Aim: The purpose of this study is to understand which marketing strategy that is most effective for restaurants on social media. The study examines how consumers' attitudes to advertising are affected depending on whether they are obtained directly through a corporate account or indirectly through influencer marketing. One part of the study is also to investigate whether an influencer's degree of expertise in the field of affairs has an impact on consumer attitudes. Method: In this deductive study we have used a quantitative method in the form of a web-based survey. The survey conducted a total of 118 responses, which then became 110 following our selection. The questionnaire was processed in SPSS and a descriptive analysis, a correlation analysis and a cluster analysis were conducted. The results were then placed against our theoretical framework to conduct a discussion that shaped our conclusions. Conclusion: This study shows that consumer attitudes are affected differently depending on the market strategy applied. The result of this study is that influencer marketing is the market strategy that has the greatest positive impact on consumer attitudes in cases where it interacts with a high level of expertise. Furthermore, this survey showed that advertising from a corporate account proved to be a reliable marketing strategy. In summary, influencer marketing is preferable if companies choose the right influences. Contribution: This study has contributed to increased understanding within the marketing strategies; influencer marketing, advertising directly from corporate accounts and how they affect consumer attitudes. The practical contribution of the study shows that restaurants should use influencer marketing with a high degree of expertise as well as advertising directly from corporate accounts to make their marketing more effective. Keywords: Social media marketing, influencer marketing, influencer, Instagram, restaurant industry, two-step flow theory, message sidedness, consumer attitudes / Titel: Välja rätt marknadsföringsstrategi på sociala medier: En studie om hur konsumenters attityder påverkas av olika marknadsföringsstrategier på Instagram. Nivå: C-Uppsats, examensarbete i företagsekonomi Författare: Tim Prasertsri, Jakob Johnson Handledare: Jonas Molin och Lars-Johan Åge Examinator: Agneta Sundström Datum: 2018 - 05 Syftet: Syftet med denna studie är att förstå vilken marknadsföringsstrategi som är mest effektiv för restauranger på sociala medier. Studien undersöker hur konsumenters attityder till reklam påverkas beroende på om den erhålls direkt via ett företagskonto eller indirekt genom influencer marketing. Ett delsyfte till denna studie är att undersöka om en influencers grad av expertis inom sakområdet har en påverkan på konsumenters attityder. Metod: I denna deduktiva studie har vi använt oss av en kvantitativ metod i form av en webbaserad enkätundersökning. Enkätundersökningen bidrog till totalt 118 svar som sedan resulterade i totalt 110 efter att vårt urval utförts. Enkätsvaren har bearbetats i SPSS och därefter genomfördes en deskriptiv analys, korrelationsanalys samt en klusteranalys. Analysresultaten ställdes sedan mot vårt teoretiska ramverk och avslutades i en diskussion som formade våra slutsatser. Slutsats: Studien visar att konsumenters attityder påverkas olika beroende på vilken marknadsföringsstrategi som tillämpas. Resultatet av denna studie är att influencer marketing är den marknadsföringsstrategi som har starkast positiv effekt på konsumenters attityder i de fall där den interagerar med en hög grad av expertis. Vidare visade denna studie att reklam direkt från företagskonton visat sig vara en reliabel marknadsföringsstrategi. Sammanfattningsvis är att influencer marketing är att föredra, om företagen väljer rätt influencer. Uppsatsens bidrag: Denna studie har bidragit till ökad förståelse inom marknadsföringsstrategierna influencer marketing och reklam direkt från företagskonton samt hur de påverkar konsumenters attityder. Studiens praktiska bidrag visar att restauranger främst bör använda sig av influencer marketing med hög grad av expertis och även reklam direkt från företagskonton för att effektivisera sin marknadsföring. Nyckelord: Social media marketing, influencer marketing, influencer, Instagram, restaurangbranschen, tvåstegshypotesen, message sidedness, konsumentattityder

O projeto ISAM apresenta uma plataforma para o desenvolvimento e a execução de aplicações pervasivas. O ambiente de execução proposto na arquitetura ISAM, denominado ISAMpe (ISAM pervasive environment), foi concebido para ser implantado em escala global, com elevado número de componentes. Esses componentes podem ser móveis ou fixos e podem apresentar limitações em seus recursos computacionais. Muitas das aplicações pervasivas que podem ser executadas no ISAMpe têm necessidade de um serviço de disseminação capaz de distribuir informações de um produtor para um grande número de consumidores. Esta dissertação apresenta um serviço de disseminação de informações para a arquitetura ISAM, denominado DIMI (Disseminador Multicast de Informações). O DIMI apresenta uma arquitetura de multicast no nível de aplicação. O DIMI propõe um algoritmo de formação da topologia de disseminação que tem o objetivo de alcançar maior escalabilidade pelo alívio de sobrecarga em participantes específicos do canal, durante os momentos em que houver um grande número de novos consumidores querendo iniciar o consumo simultaneamente. No seu ambiente-alvo, o ISAMpe, o DIMI também oferece suporte à desconexão planejada, permitindo que dispositivos computacionais com limitações de conectividade participem da disseminação, e ainda oferece suporte à mobilidade de usuários. A topologia de comunicação do DIMI adapta-se às condições da rede física subjacente a ela, de acordo com critérios específicos da aplicação que utilizar o serviço. Os resultados obtidos com a simulação de alguns aspectos do funcionamento do DIMI e com a execução do protótipo do mesmo validam os argumentos usados para justificar a necessidade e a forma de construção do serviço. / The ISAM project presents a platform to the development and to the execution of pervasive applications. The execution environment proposed by the ISAM architecture, named ISAMpe (ISAM pervasive environment) was conceived to be deployed on global scale, having a large number of components. These components may be mobile or static and may present computational resource limitations. Many of the pervasive applications that may be executed on the ISAMpe need a dissemination service capable of distribute information from one producer to many consumers. This dissertation presents a information dissemination service for the ISAM architecture, named DIMI (Multicast Information Disseminator - Disseminador Multicast de Informações). DIMI presents an application-level multicast architecture. DIMI proposes an algorithm to create the dissemination topology which objective is to achieve scalability through the relief of overload on specific participants of the channel, during the moments where many new consumers want to start consumption simultaneously. Inside its target-environment, DIMI also offer support to user mobility and to planned disconnection, allowing resource limited computational devices to be participants of the dissemination. DIMI's dissemination topology adapt itself to the conditions of fabric network, accordingly to applications' criteria. The results obtained with the simulation of some DIMI's characteristics and with prototipation validate the arguments used to justify the necessity and the way of construction of the service.

Sogeti is an IT-consulting company active in many countries. It has many different assignments and develops systems for companies in different industries. One of these assignments and systems is a system called GATA made for the company SCA's business-branch SCA SKOG. GATA stands for GPS Assisted Transport Announcement and is a comprehensive solution for timber transport from forest to industry. At this point in time, messages that do not belong to the system's main data must be sent and received outside the system. The purpose of this project has been to create a communication solution that addresses this for the system. The basic objective of the solution has been to create a local communication solution and then integrate this solution with the system. This was supposed to be done in a structured manner during sprints and with a proof-of-concept model. A local communication solution has been created consisting of a server with a message-component, a console application for creating and sending messages and a website for receiving and presenting messages. The result of the local communication solution has been proven to be consistent with the basic objective. Thereafter the local communication solution was integrated with the GATA-system. The integration resulted in a message- component being created on the system server, a console application was created within the system and a component on the system's website was created. This integrated communication solution imitates and can perform the same operations as the local communication solution and has been adapted to the GATA-system. The result of the integration and thus the entire project have been proven to be successful according to the basic target objective. / Sogeti är ett IT-konsultföretag aktivt inom många länder. Det innehar många olika uppdrag och utvecklar system till företag inom olika branscher. Ett av dessa uppdrag och system är ett system vid namn GATA skapat för företaget SCAs verksamhet SCA SKOG. GATA står för GPS Assisted Transport Announcement och är en helhetslösning för transport av timmer från skog till industri. I dagens skede måste meddelanden som inte tillhör systemets huvudsakliga data skickas och tas emot utanför systemet. Syftet med detta projekt har varit att skapa en kommunikationslösning som åtgärdar detta för systemet. Den grundläggande målbilden för lösningen har bestått av att skapa en lokal kommunikationslösning och därefter integrera denna lösning med systemet. Detta skulle göras på ett strukturerat sätt under sprinter och med en proof-of-concept modell. En lokal kommunikationslösning har skapats bestående av en server med meddelande-komponent, en konsol-applikation för att skapa och skicka meddelanden och en webbplats för att motta och presentera meddelanden. Resultatet av den lokala kommunikationslösningen har bevisats stämma överens med den grundläggande målbilden. Därefter integrerades den lokala kommunikationslösningen med GATA-systemet. Integrationen resulterade i att en meddelande-komponent skapades på systemets server, en konsol-applikation skapades inom systemet och en komponent på systemets webbplats skapades. Denna integrerade kommunikationslösning imiterar och kan utföra samma operationer som den lokala kommunikationslösningen och har anpassats till GATA-systemet. Resultatet av integrationen och därigenom hela projektet har enligt den grundläggande målbilden bevisats vara framgångsrikt.

Este trabalho se dedica à paralelização de um programa para cálculos de propriedades físicas de ligas magnéticas diluídas. O método do grupo de renormalização aplicado ao modelo de Anderson de duas impurezas se mostrou particularmente adequado ao processamento paralelo visto que grande parte dos cálculos pode ser executada simultaneamente, assim como variações nos conjuntos de dados requeridas pelo método. Para tal reescrevemos o programa seqüencial usado anteriormente pelo Grupo de Física Teórica do IFSC e implementamos três versões paralelas. Essas versões diferem entre si em relação à abordagem dada à paralelização. O uso de clusters de computadores se revelou uma opção conveniente pois verificamos que o limitante no desempenho é o tempo tomado pelos cálculos e não pela comunicação. Os resultados mostram uma grande redução no tempo total de execução, porém deficiências no speedup e escalabilidade devido a problemas de balanceamento de carga. Analisamos esses problemas e sugerimos alternativas para solucioná-los. / This dissertation discuss the parallelization of a program that calculates physical properties of dilute magnetic alloys. The renormalization group method applied to Anderson's two impurities model showed to be specially suitable to parallel processing because a large amount of calculations as well as variations of data entries required by the method can be performed simultaneously. To achieve this we rewrote the sequential program previously used by the Theoretical Physics Group of the IFSC and wrote three parallel versions. These versions differ from each other by the parallelization approach. The use of computer clusters revealed to be an appropriate option because the calculation time is the limiting factor on performance instead of communication time. The results show a good reduction of execution time, but speedup and scalability lack due to load balancing problems. We analyze these problems and suggest possible solutions.

O projeto ISAM apresenta uma plataforma para o desenvolvimento e a execução de aplicações pervasivas. O ambiente de execução proposto na arquitetura ISAM, denominado ISAMpe (ISAM pervasive environment), foi concebido para ser implantado em escala global, com elevado número de componentes. Esses componentes podem ser móveis ou fixos e podem apresentar limitações em seus recursos computacionais. Muitas das aplicações pervasivas que podem ser executadas no ISAMpe têm necessidade de um serviço de disseminação capaz de distribuir informações de um produtor para um grande número de consumidores. Esta dissertação apresenta um serviço de disseminação de informações para a arquitetura ISAM, denominado DIMI (Disseminador Multicast de Informações). O DIMI apresenta uma arquitetura de multicast no nível de aplicação. O DIMI propõe um algoritmo de formação da topologia de disseminação que tem o objetivo de alcançar maior escalabilidade pelo alívio de sobrecarga em participantes específicos do canal, durante os momentos em que houver um grande número de novos consumidores querendo iniciar o consumo simultaneamente. No seu ambiente-alvo, o ISAMpe, o DIMI também oferece suporte à desconexão planejada, permitindo que dispositivos computacionais com limitações de conectividade participem da disseminação, e ainda oferece suporte à mobilidade de usuários. A topologia de comunicação do DIMI adapta-se às condições da rede física subjacente a ela, de acordo com critérios específicos da aplicação que utilizar o serviço. Os resultados obtidos com a simulação de alguns aspectos do funcionamento do DIMI e com a execução do protótipo do mesmo validam os argumentos usados para justificar a necessidade e a forma de construção do serviço. / The ISAM project presents a platform to the development and to the execution of pervasive applications. The execution environment proposed by the ISAM architecture, named ISAMpe (ISAM pervasive environment) was conceived to be deployed on global scale, having a large number of components. These components may be mobile or static and may present computational resource limitations. Many of the pervasive applications that may be executed on the ISAMpe need a dissemination service capable of distribute information from one producer to many consumers. This dissertation presents a information dissemination service for the ISAM architecture, named DIMI (Multicast Information Disseminator - Disseminador Multicast de Informações). DIMI presents an application-level multicast architecture. DIMI proposes an algorithm to create the dissemination topology which objective is to achieve scalability through the relief of overload on specific participants of the channel, during the moments where many new consumers want to start consumption simultaneously. Inside its target-environment, DIMI also offer support to user mobility and to planned disconnection, allowing resource limited computational devices to be participants of the dissemination. DIMI's dissemination topology adapt itself to the conditions of fabric network, accordingly to applications' criteria. The results obtained with the simulation of some DIMI's characteristics and with prototipation validate the arguments used to justify the necessity and the way of construction of the service.

Made available in DSpace on 2014-06-12T15:51:19Z (GMT). No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Message Sequence Charts (MSC) é uma linguagem gráfica, usada na academia e na indústria, cujo objetivo é descrever o comportamento de componentes de sistemas e seus ambientes. A sintaxe e a semântica de um diagrama MSC padrão são definidos pelo International Telecommunication Union. A motivação para esse trabalho foi originada a partir de esforços para modelar cenários de aplicações de aparelhos móveis com o objetivo de automatizar a geração de testes, no contexto de uma colaboração entre Centro de Informática da Universidade Federal de Pernambuco (CIn- UFPE) e a Motorola, no contexto do projeto Brasil Test Center (BTC). Ao modelar algumas destas aplicações que envolvem múltipla sincronização utilizando como linguagem de modelagem, MSC padrão, constatou-se que os diagramas são de difícil entendimento ou com um comportamento diferente do desejado. É proposta neste trabalho uma extensão de MSC com o objetivo de permitir a descrição de mensagens síncronas, que permitem descrever eventos instantâneos (abstraindo-se a duração do tempo real para que a conexão seja estabelecida) e podendo envolver várias instâncias de MSC. Essa extensão é conservativa, no sentido que o comportamento das construções existentes não é afetado pela mesma; além disso, em um mesmo diagrama é possível conter mensagens síncronas e mensagens assíncronas. Foi desenvolvido um algoritmo de transformação, que a partir de um diagrama escrito na notação MSC estendido, gera um diagrama correspondente na notação de MSC padrão. Este algoritmo tem por objetivo permitir a transitividade entre as notações e demonstrar suas equivalências. Este algoritmo de transformação implementa mensagens síncronas como uma seqüência de mensagens assíncronas seguindo um algoritmo particular de handshake. A segunda contribuição desse trabalho é a definição de uma semântica para a notação padrão e estendida de MSC. Essa definição é dada em termos da álgebra de processos CSP (Communicating Sequential Processes). O formalismo introduzido na notação de Message Sequence Charts com CSP permite mostrar a equivalência entre um diagrama na notação de MSC estendido e seu correspondente descrito em MSC padrão, gerado a partir do algoritmo de transformação. Além disso, modelar MSC como um processo descrito na notação CSP permite uma análise sobre seus diagramas, usando um rico conjunto de leis algébricas de CSP, bem como o uso de ferramentas, como FDR2 e o Probe. Finalmente, para validar a estratégia proposta, desenvolveu-se um exemplo que ilustra a utilização da notação estendida de MSC, notação síncrona; a conversão desta notação para a notação padrão e a equivalência entre o MSC estendido e o padrão. Mostramos, ainda, o uso da ferramenta Power Tool Kit(PTK) para geração de casos de teste a partir de diagramas MSC

Capturing a requirement is a great challenge in the initial stages of the software development, be it a system requirement or a customer requirement to the software engineers. Understanding the requirement and predicting or differentiating what may happen and what must happen is difficult especially in the complex real time systems. Live sequence charts are extensions of the message sequence charts which can specify the live ness of the requirements. And the play engine tool is used to specify, validate, and analyze the scenarios of the requirements. This thesis is to evaluate live sequence charts using the play engine tool and to see if the built-in model checkers can detect inconsistencies in the LSC’s. / The requirements capturing and analysis has always been the initial criteria and main problem during the software design and development for the software engineers. It’s been very common to use natural language for capturing the requirements in the industries because of its ease of use. The graphical languages were used to represent the requirements, its behavior and the scenarios graphically or visually, for example UML. UML Sequence diagrams are used in the real time software development to capture the requirements which specifies the scenarios of the system behavior and also the interactions between the objects graphically. Message sequence charts are also a graphical language for representing the scenarios and also the behavior of the system especially in the telecommunication domain. But these two are only useful in specifying the one aspect of the behavior and not much helpful in specifying the liveness of the requirement. Liveness can be defined as something good will happen [34] or something must happen. For this reason live sequence charts were developed which can specify the liveness of the requirement. Live sequence charts are capable of specifying the scenarios what may happen and what must happen. This thesis is to evaluate the live sequence charts using the play engine tool running on the windows machine and also to study the built in model checkers for formal verification. The thesis starts with the various types of graphical representation of requirements in Software Engineering, followed by the Research Methodology, next a bit more explanation of Live Sequence Charts, Evaluation, Result, Conclusions and Lessons Learned from the thesis. / Permanent Address: C/O: K.VIJAYA H.NO. 3-1-39/12/3/2 TEACHER'S COLONY ARMOOR-503224 ANDHRAPRADESH INDIA.

Voice over IP (VoIP) services based on Session Initiation Protocol (SIP) has gained much attention as compared to other protocols like H.323 or MGCP over the last decade. SIP is the most favorite signaling protocol for the current and future IP telephony services, and it‘s also becoming the real competitor for traditional telephony services. However, the open architecture of SIP results the provided services vulnerable to different types of security threats which are similar in nature to those currently existing on the Internet. For this reason, there is an obvious need to provide some kind of security mechanisms to SIP based VOIP implementations. In this research, we will discuss the security threats to SIP and will highlight the related open issues. Although there are many threats to SIP security but we will focus mainly on the session hijacking and DoS attacks. We will demonstrate these types of attacks by introducing a model/practical test environment. We will also analyze the effect and performance of some the proposed solutions that is the use of Network Address Translation (NAT), IPSec, Virtual Private Networks (VPNs) and Firewalls (IDS/IPS) with the help of a test scenario.