Cette thèse porte sur la représentation littéraire de l’échange prostitutionnel dans son rapport ambigu au contrat, à l’intimité et à la rencontre. Elle est basée sur une analyse de textes de Villiers de L’Isle-Adam, Maupassant, Flaubert, Arcan, Duras, et du tableau Olympia de Manet. Dans un premier temps, je m’intéresse à un motif abordé par certains textes du corpus, et devenu lieu commun, celui qui fait de la prostitution la métaphore et l’extension du capitalisme en tant que ce dernier « réifie le monde », et j’en montre les divers déploiements. Dans un second temps, j’analyse des œuvres qui mettent de l’avant l’échange prostitutionnel en reprenant un autre rapport qu’il entretient avec le marché (intimement lié au premier) : celui de la clôture de la relation induite par le contrat. Les textes à l’étude problématisent cette rencontre « annulée ». En cela, je m’arrête d’une part sur l’invention d’un « dépassement » du contrat vers l’intimité, et de l’autre sur la mise en scène, rejouée dans l’échange prostitutionnel, d’un empêchement de la relation. Comment la prostitution figure-t-elle en tant que métaphore péjorative de la vénalité ? Comment devient-elle par ailleurs le lieu de la répétition d’une impossible rencontre sexuelle « véritable » ? Alimentée par ces questions, cette thèse analyse les représentations de l’échange prostitutionnel dans la littérature comme lieu paradigmatique du contrat, paradoxalement travaillé de l’intérieur par l’invention d’une rencontre toujours occupée à ne pas se faire. / This thesis focuses on the literary representation of prostitutional exchange in its ambiguous relationship to the concepts of contract, intimacy and encounter. It is based on an analysis of texts by Villiers de L'Isle-Adam, Maupassant, Flaubert, Arcan and Duras, as well as Manet's painting, Olympia. First, I focus on a theme addressed by some writings within the corpus which has become commonplace: the idea of prostitution as the too wide extension of capitalism, as it “reifies the world.” I show the various deployments of this metaphor. In a second step, I analyze literary works that put forward the prostitutional exchange by returning to another relationship that it maintains with the market (intimately linked to the first): that of the closure and the clarity of the rapport allowed by the contract. The texts offered for study herein problematize this “cancelled” meeting. In this, I address on the one hand the development of “surpassing” of the contract towards intimacy, and on the other, on the staging, replayed in the prostitutional exchange, of an impediment of the relationship. How does prostitution become the pejorative metaphor for venality? How does it also become the place of repetition of an impossible “real” sexual encounter? These queries spark others to unfold through the thesis, in that the latter questions the prostitutional exchange in literature as a paradigmatic place of the contract, paradoxically developed from within by the invention of an encounter constantly yearning to be inexistant.

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No / Security mechanisms, such as encryption and authentication protocols, require extra computing resources and therefore, have an adverse effect upon the performance of robotic mobile wireless ad hoc networks (RANETs). Thus, an optimal performance and security trade-off should be one of the main aspects that should be taken into consideration during the design, development, tuning and upgrading of such networks. In this context, an exposition is initially undertaken on the applicability of Petri nets (PNs) and queueing networks (QNs) in conjunction with their generalisations and hybrid integrations as robust quantitative modelling tools for the performance analysis of discrete flow systems, such as computer systems, communication networks and manufacturing systems. To overcome some of the inherent limitations of these models, a novel hybrid modelling framework is explored for the quantitative evaluation of RANETs, where each robotic node is represented by an abstract open hybrid G-GSPN_QN model with head-of-line priorities, subject to combined performance and security metrics (CPSMs). The proposed model focuses on security processing and state-based control and it is based on an open generalised stochastic PN (GSPN) with a gated multi-class 'On-Off' traffic and mobility model. Moreover, it employs a power consumption model and is linked in tandem with an arbitrary QN consisting of finite capacity channel queues with blocking for 'intra' robot component-to-component communication and 'inter' robot-to-robot transmission. Conclusions and future research directions are included.

Cognitive radio is frequently touted as a platform for implementing dynamic distributed radio resource management algorithms. In the envisioned scenarios, radios react to measurements of the network state and change their operation according to some goal driven algorithm. Ideally this flexibility and reactivity yields tremendous gains in performance. However, when the adaptations of the radios also change the network state, an interactive decision process is spawned and once desirable algorithms can lead to catastrophic failures when deployed in a network. This document presents techniques for modeling and analyzing the interactions of cognitive radio for the purpose of improving the design of cognitive radio and distributed radio resource management algorithms with particular interest towards characterizing the algorithms' steady-state, convergence, and stability properties. This is accomplished by combining traditional engineering and nonlinear programming analysis techniques with techniques from game to create a powerful model based approach that permits rapid characterization of a cognitive radio algorithm's properties. Insights gleaned from these models are used to establish novel design guidelines for cognitive radio design and powerful low-complexity cognitive radio algorithms. This research led to the creation of a new model of cognitive radio network behavior, an extensive number of new results related to the convergence, stability, and identification of potential and supermodular games, numerous design guidelines, and several novel algorithms related to power control, dynamic frequency selection, interference avoidance, and network formation. It is believed that by applying the analysis techniques and the design guidelines presented in this document, any wireless engineer will be able to quickly develop cognitive radio and distributed radio resource management algorithms that will significantly improve spectral efficiency and network and device performance while removing the need for significant post-deployment site management. / Ph. D.

Als Bild- und Medientheoretiker hinterließ Walter Benjamin nicht nur die berühmte „materialistische“ Auratheorie, sondern auch scheinbar esoterische Theorien der bildenden Kunst. Der Zusammenhang und Inhalt der beiden Theorien können erhellt werden, wenn wir genauer sehen, wie er sich dort mit der Beschreibung der Kindheit beschäftigte. Der Ursprung seiner Auratheorie liegt in seiner „Tagebuch“-Literatur, wo er in die melancholisch gefärbten Visionen der „Jugend“ zu versinken pflegte. Der topologische Aufbau dieser Visionen – ihre eigenartig „photo-graphische“ Struktur – soll mithilfe der Zweiten Topik Freuds analysiert werden. Und aufgrund dieser Analyse werden wir eine Revision der üblichen (übersimplifizierten) Gegenüberstellung von seinem historischen Materislismus und dem „apolitischen Formalismus“ Clement Greenbergs vornehmen. Greenbergs Kunstkritik dient aber auch zur Entschlüsselung der „esoterischen“ Bildtheorien Benjamins. Die letzteren verwirren uns vor allem deshalb, weil dort das Sehen der Kinder zuerst (um 1915) irreführender Weise nach den üblichen Dichotomien der Romantik (Linie / Farbe; männlich / weiblich; erwachsen / kindlich…) beschrieben worden war; ihren eigentlichen Inhalt konnte Benjamin erst präzisieren, als er – anhand seiner Betrachtungen der graphischen „Horizontalität“ und nach seinen Spekulationen über das magische Wesen von „Zeichen“ und „Mal“ (1917) – eine Trichotomie der Bildgattungen (Malerei / Graphik / getuschtes Bild) aufgestellt hatte. Wir rekonstruieren diese Theorieentwicklungen nicht nur durch detaillierte Bild- und Textanalysen, sondern auch unter Heranziehung seines „materialistischen“ Spätwerks (der Passagenarbeit und der „Berliner Kindheit“), da erst im letzteren der einzigartige Zusammenhang zwischen seinen frühen Bildtheorien und seiner Geldtheorie als „Konstellation“ sichtbar werden sollte. / Walter Benjamin’s writings on visual arts include not only the famous „materialistic“ essays on aura but also seemingly esoteric notes on painting and the graphic arts. The content and correlation of all these writings become clear once we grasp how they perform the task of describing childhood experience. His theory of aura was prefigured in his philosophical „Diaries“ where his struggle with his depression was often followed (or interrupted) by dreamlike visions of "youth". The discursive structure of these visions – which will prove to be a strangely „photo-graphic“ one – is to be analyzed by using the second Freudian topology as a comparison. Through this analysis we will be able to reconsider the well-known (oversimplified) antagonism between his historical materialism and the „apolitical formalism“ of Clement Greenberg from a new viewpoint. Greenberg’s criticism helps us also to decipher the „esoteric“ texts of Benjamin. They puzzled scholars especially because they described children’s vision at first (about 1915) misleadingly in accordance with the conventional dichotomies of Romanticism (line / color; masculine / feminine; adult / child…); Benjamin could specify their original implication only after he had set up – based on his reflexions on the „horizontality“ of the graphic arts, and by speculating further on the magic nature of „Zeichen“ and „Mal“ (1917) – a trichotomy of genres (painting / the graphic arts / ink and watercolor illustrations). We will reconstruct this development of his theory not only through detailed analyses of related works of art but also in view of his „materialistic“ late writings (the Arcades Project and „Berlin Childhood“), for it is only there that we find out an essential relation – a singular „constellation“ – of his early art theory and his theory of money.

Vehicular ad hoc networks (VANETs) are a subclass of mobile ad hoc networks (MANETs) in which the mobile nodes are vehicles; these vehicles are autonomous systems connected by wireless communication on a peer-to-peer basis. They are self-organized, self-configured and self-controlled infrastructure-less networks. This kind of network has the advantage of being able to be set-up and deployed anywhere and anytime because it has no infrastructure set-up and no central administration. Distributing information between these vehicles over long ranges in such networks, however, is a very challenging task, since sharing information always has a risk attached to it especially when the information is confidential. The disclosure of such information to anyone else other than the intended parties could be extremely damaging, particularly in military applications where controlling the dissemination of messages is essential. This thesis therefore provides a review of the issue of security in VANET and MANET; it also surveys existing solutions for dissemination control. It highlights a particular area not adequately addressed until now: controlling information flow in VANETs. This thesis contributes a policy-based framework to control the dissemination of messages communicated between nodes in order to ensure that message remains confidential not only during transmission, but also after it has been communicated to another peer, and to keep the message contents private to an originator-defined subset of nodes in the VANET. This thesis presents a novel framework to control data dissemination in vehicle ad hoc networks in which policies are attached to messages as they are sent between peers. This is done by automatically attaching policies along with messages to specify how the information can be used by the receiver, so as to prevent disclosure of the messages other than consistent with the requirements of the originator. These requirements are represented as a set of policy rules that explicitly instructs recipients how the information contained in messages can be disseminated to other nodes in order to avoid unintended disclosure. This thesis describes the data dissemination policy language used in this work; and further describes the policy rules in order to be a suitable and understandable language for the framework to ensure the confidentiality requirement of the originator. This thesis also contributes a policy conflict resolution that allows the originator to be asked for up-to-date policies and preferences. The framework was evaluated using the Network Simulator (NS-2) to provide and check whether the privacy and confidentiality of the originators’ messages were met. A policy-based agent protocol and a new packet structure were implemented in this work to manage and enforce the policies attached to packets at every node in the VANET. Some case studies are presented in this thesis to show how data dissemination can be controlled based on the policy of the originator. The results of these case studies show the feasibility of our research to control the data dissemination between nodes in VANETs. NS-2 is also used to test the performance of the proposed policy-based agent protocol and demonstrate its effectiveness using various network performance metrics (average delay and overhead).

Security of communications is a major requirement for Mobile Adhoc NETworks(MANETs) since they use wireless channel for communications which can be easily tapped, and physical capture of MANET nodes is also quite easy. From the point of view of providing security in MANETs, there are basically two types of MANETs, viz., authoritarian MANETs, in which there exist one or more authorities who decide the members of the network, and self-organized MANETs, in which there is no such authority. Ensuring security of communications in the MANETs is a challenging task due to the resource constraints and infrastructure-less nature of these networks, and the limited physical security of MANET nodes. Attacks on security in a MANET can be launched by either the external attackers which are not legitimate members of the MANET or the internal attackers which are compromised members of the MANET and which can hold some valid security credentials or both. Key management and authentication protocols(KM-APs)play an important role in preventing the external attackers in a MANET. However, in order to prevent the internal attackers, an intrusion detection system(IDS) is essential. The routing protocols running in the network layer of a MANET are most vulnerable to the internal attackers, especially to the attackers which launch packet dropping attack during data packet forwarding in the MANET. For an authoritarian MANET, an arbitrated KM-AP protocol is perfectly suitable, where trusts among network members are coordinated by a trusted authority. Moreover, due to the resource constraints of a MANET, symmetric key management protocols are more efficient than the public key management protocols in authoritarian MANETs. The existing arbitrated symmetric key management protocols in MANETs, that do not use any authentication server inside the network are susceptible to identity impersonation attack during shared key establishments. On the other hand, the existing server coordinated arbitrated symmetric key management protocols in MANETs do not differentiate the role of a membership granting server(MGS) from the role of an authentication server, and so both are kept inside the network. However, keeping the MGS outside the network is more secure than keeping it inside the network for a MANET. Also, the use of a single authentication server inside the network cannot ensure robustness against authentication server compromise. In self-organized MANETs, public key management is more preferable over symmetric key management, since the distribution of public keys does not require a pre-established secure channel. The main problem for the existing self-organized public key management protocols in MANETs is associated with the use of large size certificate chains. Besides, the proactive certificate chaining based approaches require each member of a MANET to maintain an updated view of the trust graph of the entire network, which is highly resource consuming. Maintaining a hierarchy of trust relationships among members of a MANET is also problematic for the same reason. Evaluating the strength of different alternative trust chains and restricting the length of a trust chain used for public key verification is also important for enhancing the security of self-organized public key management protocols. The existing network layer IDS protocols in MANETs that try to defend against packet dropping attack use either a reputation based or an incentive based approach. The reputation based approaches are more effective against malicious principals than the incentive based approaches. The major problem associated with the existing reputation based IDS protocols is that they do not consider the protocol soundness issue in their design objectives. Besides, most of the existing protocols incorporate no mechanism to fight against colluding principals. Also, an IDS protocol in MANETs should incorporate some secure and efficient mechanism to authenticate the control packets used by it. In order to mitigate the above mentioned problems in MANETs, we have proposed new models and designed novel security protocols in this thesis that can enhance the security of communications in MANETs at lesser or comparable cost. First, in order to perform security analysis of KM-AP protocols, we have extended the well known strand space verification model to overcome some of its limitations. Second, we have proposed a model for the study of membership of principals in MANETs with a view to utilize the concept for analyzing the applicability and the performance of KM-AP protocols in different types of MANETs. Third and fourth, we have proposed two novel KM-AP protocols, SEAP and CLPKM, applicable in two different types of MANET scenarios. The SEAP protocol is an arbitrated symmetric key management protocol designed to work in an authoritarian MANET, whereas the CLPKM protocol is a self-organized public key management protocol designed for self-organized MANETs. Fifth, we have designed a novel reputation based network layer IDS protocol, named EVAACK protocol, for the detection of packet dropping misbehavior in MANETs. All of the three proposed protocols try to overcome the limitations of the existing approaches in their respective categories. We have provided rigorous mathematical proofs for the security properties of the proposed protocols. Performance of the proposed protocols have been compared with those of the other existing similar approaches using simulations in the QualNet simulator. In addition, we have also implemented the proposed SEAP and CLPKM protocols on a real MANET test bed to test their performances in real environments. The analytical, simulation and experimentation results confirm the effectiveness of the proposed schemes.