A dissertação investiga possibilidades formais de articulação entre universos pessoais e processos históricos no campo da realização documentária em primeira pessoa. O ponto de partida são materiais e procedimentos advindos de um documentário de longa-metragem que atualmente desenvolvo, intitulado Bem vindos de novo. O filme aborda as experiências da minha família na imigração de nipo-brasileiros para o Japão, conhecida como \"fenômeno decasségui\". Nele, busco articular as experiências pessoais e familiares com aspectos mais amplos desse acontecimento histórico e social, de proporções internacionais, que atingiu, e continua afetando diretamente, cerca de 600 mil pessoas. Abordo três procedimentos formais empregados no filme: (1) a utilização de fotografias domésticas; (2) a elaboração da narração em voz over; (3) o emprego de filmagens históricas realizadas por Hikoma Udihara, colonizador e cinegrafista pioneiro da imigração japonesa no Brasil. Através do mapeamento de possibilidades formais relacionadas aos procedimentos em questão, busco identificar e analisar um conjunto de conceitos, de instrumentos críticos e teóricos, úteis para se pensar a articulação entre o íntimo e o histórico, o pessoal e o social, em documentários na primeira pessoa; em diálogo constante com aspectos concretos da realização cinematográfica. / This master\'s thesis investigates formal possibilities of articulation between personal universes and historical processes inside the first person filmmaking practice. The bases are materials and procedures related to a feature documentary film that I am now developing, called Welcome Back, Farewell (Bem vindos de novo). The film addresses my family experiences in immigration of Japanese-Brazilians to Japan, known as \"dekassegui phenomenon\". In the film, I try to articulate personal and familiar experiences with wider features of this historical and social event of international proportion, which reached, and still concerns directly to six hundreds thousand people. Three formal procedures of the film are covered: (1) the use of domestic photography; (2) the elaboration of the voice over narration; (3) the usage of historical footage produced by Hikoma Udihara, colonizer and pioneer amateur filmmaker of the Japanese immigration in Brazil. Through the organization of formal possibilities related with the previous procedures, the aim is to identify and analyze a group of concepts, of critical and theoretical devices, useful to think the articulation between the intimate and the historical, the personal and the social, within the first person documentary; in frequent contact with concrete features of the filmmaking practice.

Dans cette thèse, je propose trois contributions principales : dans notre première contribution, nous étudions l'architecture d'identité WebRTC et plus particulièrement son intégration aux algorithmes de délégation d'authentification existants. Cette intégration n'a pas encore été étudiée jusqu'à présent. Dans cette perspective, nous implémentons les composants de l'architecture d'identité WebRTC ce qui nous permet de montrer que cette architecture n'est pas particulièrement adaptée à une intégration aux protocoles de délégation d'authentification existants tels qu'OpenID Connect. Pour répondre à RQ1, nous montrons ensuite comment la position centrale des fournisseurs d'identité dans l'écosystème du Web est renforcée par leur intégration à l'établissement de session WebRTC, posant ainsi un risque supplémentaire contre la discrétion des utilisateurs. Dans l'écosystème Web, la norme est l'architecture des services en silo dont les utilisateurs sont captifs. C'est en particulier le cas des systèmes de délégation d'authentification, pour lesquels la plupart du temps, il n'est pas possible de choisir son fournisseur d'identité. Afin de répondre à RQ3, nous réalisons une étude afin de déterminer pour quelles raisons les utilisateurs ne peuvent pas choisir leur fournisseur d'identité sur Web. Notre étude montre que bien que ce choix soit possible en théorie, l'absence d'implémentation de certains standards par les sites webs et les fournisseurs d'identité empêche ce choix en pratique. Dans notre seconde contribution, nous cherchons à donner plus de contrôle à l'utilisateur. Pour ce faire et en réponse à RQ2, nous proposons une extension de la spécification WebRTC afin de permettre la négociation des paramètres d'identité. Un prototype d'implémentation est proposé afin de valider notre proposition. Cette implémentation révèle certaines limites dues à l'API d'identité WebRTC empêchant notamment d'obtenir un retour sur le niveau d'authentification de l'autre utilisateur ainsi que l'impossibilité de changer de fournisseur d'identité en cours de session. Nous proposons ensuite une API Web permettant aux utilisateurs de choisir leur fournisseur d'identité lors d'une authentification sur un site tiers via une interface de sélection d'identité contrôlée par le navigateur. Répondant à RQ3, notre API repose sur une réutilisation de l'architecture d'identité WebRTC dans un scénario client-serveur. Nous présentons une implémentation de notre solution, basée sur une extension du navigateur Firefox, afin d'en démontrer l'utilisabilité. Nos résultats montrent qu'à long terme, l'adoption de cette API pourrait réduire la charge d'implémentation pour les développeurs de sites Web et permettre aux utilisateurs de préserver leur discrétion en choisissant des fournisseurs d'identité de confiance. / In this thesis, we propose three main contributions : In our first contribution we study the WebRTC identity architecture and more particularly its integration with existing authentication delegation protocols. This integration has not been studied yet. To fill this gap, we implement components of the WebRTC identity architecture and comment on the issues encountered in the process. In order to answer RQ1, we then study this specification from a privacy perspective an identify new privacy considerations related to the central position of identity provider. In the Web, the norm is the silo architecture of which users are captive. This is even more true of authentication delegation systems where most of the time it is not possible to freely choose an identity provider. In order to answer RQ3, we conduct a survey on the top 500 websites according to Alexa.com to identify the reasons why can't users choose their identity provider. Our results show that while the choice of an identity provider is possible in theory, the lack of implementation of existing standards by websites and identity providers prevent users to make this choice. In our second contribution, we aim at giving more control to users. To this end and in order to answer RQ2, we extend the WebRTC specification to allow identity parameters negotiation. We present a prototype implementation of our proposition to validate it. It reveals some limits due to the WebRTC API, in particular preventing to get feedback on the other peer's authentication strength. We then propose a web API allowing users to choose their identity provider in order to authenticate on a third-party website, answering RQ2. Our API reuse components of the WebRTC identity architecture in a client-server authentication scenario. Again, we validate our proposition by presenting a prototype implementation of our API based on a Firefox extension. Finally, in our third contribution, we look back on RQ1 and propose a trust and security model of a WebRTC session. Our proposed model integrates in a single metric the security parameters used in the session establishment, the encryption parameters for the media streams, and trust in actors of the communication setup as defined by the user. Our model objective is to help non-expert users to better understand the security of their WebRTC session. To validate our approach, we conduct a preliminary study on the comprehension of our model by non-expert users. This study is based on a web survey offering users to interact with a dynamic implementation of our model.

<p>With the constant development of wireless technologies, the usageof wireless devices tends to increase even more in the future.Wireless multi-hop networks (WMNs) have emerged as a keytechnology to numerous potential scenarios, ranging from disasterrecovery to wireless broadband internet access. The distributedarchitecture of WMNs enables nodes to cooperatively relay othernode's packets. Because of their advantages over other wirelessnetworks, WMNs are undergoing rapid progress and inspiringnumerous applications. However, many technical issues still existin this field. In this thesis we investigate how Voice over IP(VoIP) and peer-to-peer (P2P) application are influenced bywireless multi-hop network characteristics and how to optimizethem in order to provide scalable communication.We first consider the deployment of VoIP service in wirelessmulti-hop networks, by using the Session Initiation Protocol (SIP)architecture. Our investigation shows that the centralized SIParchitecture imposes several challenges when deployed in thedecentralized wireless multi-hop environment. We find that VoIPquality metrics are severely degraded as the traffic and number ofmultiple hops to the gateway increase. In the context ofscalability, we further propose four alternative approaches whichavoid current limitations.In the second part of this thesis we tackle the network capacityproblem while providing scalable VoIP service over wirelessmulti-hop networks. The performance evaluation shows the influenceof intra and inter-flow interference in channel utilization, whichdirect impacts the VoIP capacity. In order to avoid the small VoIPpacket overhead, we propose a new adaptive hop-by-hop packetaggregation scheme based on wireless link characteristics. Ourperformance evaluation shows that the proposed scheme can increasethe VoIP capacity by a two-fold gain.The study of peer-to-peer applicability over wireless multi-hopnetworks is another important contribution. A resource lookupapplication is realized through structured P2P overlay. We showthat due to several reasons, such as characteristics of wirelesslinks, multi-hop forwarding operation, and structured P2Pmanagement traffic aggressiveness the performance of traditionalP2P applications is rather low in wireless multi-hop environments.Therefore, we suggested that a trade-off between the P2P lookupefficiency and the P2P management traffic overhead can be achievedwhile maintaining the overlay network consistency in wirelessmulti-hop networks.</p>

Die "Mitteilungen des URZ" informieren die Nutzer des Universitätsrechenzentrums der TU Chemnitz umfassend über neue Dienste und Projekte, vermitteln ggf. Hintergrundwissen und dienen der Berichterstattung.

Θα περιγράψουμε τις βασικές λειτουργίες ενός VoIP δικτύου, τα συστατικά του μέρη, καθώς και τα πρωτόκολλα που είναι υπεύθυνα για την εγκατάσταση, τον έλεγχο και τον τερματισμό μιας VoIP υπηρεσίας-συνομιλίας. Τα πρωτόκολλα αυτά ονομάζονται πρωτόκολλα σηματοδοσίας. Τα πρωτόκολλα σηματοδοσίας για VoIP εφαρμογές και ιδιαίτερα το πρωτόκολλο SIP (Session Initiation Protocol) είναι το βασικό θέμα της παρούσας εργασίας. Συγκεκριμένα, έγινε ανάπτυξη ενός SIP User Agent, το λογισμικό του οποίου θα εκτελείται στο δικτυακό επεξεργαστή IXP425 της Intel, μαζί με τα απαραίτητα πρωτόκολλα για την κωδικοποίηση-αποκωδικοποίηση και μετάδοση δειγμάτων φωνής σε μορφή πακέτων δεδομένων. Το αποτέλεσμα αναμένεται να είναι ένα ολοκληρωμένο προϊόν (VoIP phone) για την πραγματοποίηση VoIP κλήσεων. / -

Ce travail est un défrichement qui cherche à explorer les usages de la voix-over dans le cinéma documentaire. Questionnant sa nature éminemment hétérogène, cette étude de la voix dans le registre over portera d'abord sur sa matérialité dans le champ du sonore, avant de s'attarder à ses fonctions dans l'élaboration du discours documentaire. Comme il s'agit d'une entreprise nouvelle, il y aura de nombreux aller-retours entre les très rares études menées sur la voix-over–presque exclusivement circonscrites au cinéma de fiction (Kozloff, Châteauvert, Boillat)–et différents travaux théoriques et critiques traitant des enjeux de la représentation du réel dans le cinéma documentaire (Nichols, Niney, Gauthier). Cela permettra de mettre en lumière le cas du cinéma documentaire où la voix-over occupe des fonctions beaucoup moins narratives que discursives. Il sera vu comment cette parole (comme occurrence sonore et comme productrice de sens) est posée par-dessus (over) les images, entretenant avec elles des rapports d'interdépendance parfois convergents, mais parfois divergents. On comprendra aussi que dans son usage spécifiquement documentaire, la voix-over contribue à rendre plus manifeste la prise de parole d'un sujet sensible et pensant qui offre ni plus ni moins une interprétation du monde. Aussi, ce mémoire est un diptyque. Le présent texte doit donc être considéré en correspondance avec le film documentaire D'où, chose étonnante, rien ne s'en suit, qui constitue le deuxième volet de l'ouvrage. Mots clés : cinéma, documentaire, voix-over, parole, son. / This exploratory thesis examines the various practices of voice-over in documentary film. Questioning the highly heterogeneous nature of voice in the over register, I first discuss it with respect to the material aspects of sound before examining it’s functions in the elaboration of documentary discourse. Because this is a new undertaking, I will travel back- and-forth between the rare studies concerning voice-over–almost exclusively confined to fiction film (Kozloff, Châteauvert, Boillat)–and works proposing different theoretical and critical views on the representation of reality in documentary films (Nichols, Niney, Gauthier). This will help bring to light the specificities of documentay cinema where voice- over is used less towards the production of a narrative and more towards the articulation of discourse. With the help of examples from a range of documentary films, I will show how speech (both as an occurrence of sound and as a means of producing meaning) is placed over the images, in a sometimes converging, but sometimes diverging, interdependent relationship. This will help demonstrate that the specific use of voice-over in documentary film makes manifest the act of speech of the sensitive, thinking subject who offers, no more no less, than an interpretation of the world. Also, this thesis is a diptych and needs to be considered in correspondence with the documentary film D'où, chose étonnante, rien ne s'en suit that constitutes second part of the work. Keywords : cinema, documentary, voice-over, speech, sound. / Il s'agit d'une maîtrise-création donc le texte s'accompagne du film en fichier complémentaire.

På papiret virker Fight Club [1999] som et sikkert stikk. En litterær adapsjon utført av en kjent regissør (David Fincher) med solide stjernenavn på plakaten(Brad Pitt, Edward Norton). Men Chuck Palahniuks debutroman fra 1996 er et vanskelig verk, preget av mørk satire, flere lag med ironi og radikal subjektivitet. For å oversette en slik fortelling til film trengs ikke bare dristigheten til å fortelle om kontroversielle tema, men også oppfinnsomheten til å oversette en utpreget psykologisk roman til et audiovisuelt språk. Det er nettopp oversettelsen jeg skal undersøke i denne oppgaven, hvordan romanens kildemateriale har blitt gjenskapt i filmmediet. For å gjøre dette så konkret som mulig, snevrer jeg først inn undersøkelsen til filmens voice-over, som er basert på romanens tekst. Hvordan har bokas fortellerstemme blitt adaptert til en fortellende voice-over i filmen? Jeg skal ta for meg denne prosessen i tre deler, basert på tre stadier i adapsjonsprosessen hvor filmskaperne har hatt anledning til å kreativt bearbeide romanens tekst. Første del er voice-overen sett som skriftlig tekst, manusstadiet. Hva er kuttet, forandret og lagt til romanens tekst? Andre del er voice-overen som stemme, innspillingsstadiet. Hvordan forandres skriften i manus, og dermed også romanens tekst, idet en den blir til uttalte ord? Hvilke virkemidler har filmskaperne her benyttet seg av? Tredje del er fortellerstemmen i møte med resten av filmspråket, klippestadiet. Hvordan påvirker bildene og den øvrige lyddesignen vår opplevelse av fortellerstemmen, og hvordan er påvirkningen den andre veien? Deretter skal jeg utvide perspektivet igjen, og undersøke hvilke implikasjoner bruken av voice-over har for filmen som helhet. Hva kan en film kommuniserer Fight Club på denne måten? Tema blir ironi, upålitelighet, subjektivitet, karakterengasjement og kronologi. Anvendte teoretikere inkluderer Linda Hutcheon, Sarah Kozloff, Thomas Elsaesser, Gerard Genette, Seymour Chatman, André Bazin, Murray Smith og Lars Thomas Braaten.

If not the most, one of the serious threats to data networks, particularly pervasive commercial networks such as Voice-over-IP (VoIP) providers is Denial-of-Service (DoS) attack. Currently, majority of solutions for these attacks focus on observing detailed server state changes due to any or some of the incoming messages. This approach however requires significant amount of server’s memory and processing time. This results in detectors not being able to scale up to the network edge points that receive millions of connections (requests) per second. To solve this problem, it is desirable to design stateless detection mechanisms. One approach is to aggregate transactions into groups. This research focuses on stateless scalable DoS intrusion detection mechanisms to obviate keeping detailed state for connections while maintaining acceptable efficiency. To this end, we adopt a two-layer aggregation scheme termed Advanced Partial Completion Filters (APCF), an intrusion detection model that defends against DoS attacks without tracking state information of each individual connection. Analytical as well as simulation analysis is performed on the proposed APCF. A simulation test bed has been implemented in OMNET++ and through simulations it is observed that APCF gained notable detection rates in terms of false positive and true positive detections, as opposed to its predecessor PCF. Although further study is needed to relate APCF adjustments to a certain network situation, this research shows invaluable gain to mitigate intrusion detection from not so scalable state-full mechanisms to aggregate scalable approach.

The rapid growth of the Internet and the proliferation of its new applications pose a serious challenge in network performance management and monitoring. The current Internet has no mechanism for providing feedback on network congestion to the end-systems at the IP layer. For applications and their end hosts, end-to-end measurements may be the only way of measuring network performance. Understanding the packet delay and loss behavior of the Internet is important for proper design of network algorithms such as routing and flow control algorithms, for the dimensioning of buffers and link capacity, and for choosing parameters in simulation and analytic studies. In this thesis, round trip time (RTT), one-way network delay and packet loss in the Internet are measured at different times of the day, using a Voice over IP (VoIP) device. The effect of clock skew on one-way network delay measurements is eliminated by a Linear Programming algorithm, implemented in MATLAB. Distributions of one-way network delay and RTT in the Internet are determined. It is observed that delay distribution has a gamma-like shape with heavy tail. It is tried to model delay distribution with gamma, lognormal and Weibull distributions. It is observed that most of the packet losses in the Internet are single packet losses. The effect of firewall on delay measurements is also observed.

Σκοπός της παρούσας διπλωματικής εργασίας ήταν η μελέτη των παραμέτρων που επηρεάζουν την ποιότητα εξυπηρέτησης (QoS – Quality of Service) των εφαρμογών VoIP μέσω των διαφόρων τεχνολογιών ευρυζωνικής πρόσβασης. / Aim of the present diplomatic assigment was the study of parameters that affect the quality of service (QoS) of VoIP applications via the various broadband access technologies.