Objetivo dessa tese é trazer uma visão ampla do Hip Hop. Diferentemente do que se têm afirmado em outras pesquisas, no nosso caso interessa tomar o movimento como conjunto, a fim de entender de que maneira, de um lado, existem diversas formas de compreender esse fenômeno e, de outro, como a dicotomia entre política e cultura torna-se central num debate. Antes de reiterar a polaridade nossa meta é mostrar como esses conceitos dialogam, e de uma forma e a um só tempo, tensa e ambígua. Para tanto analisamos o Hip Hop paulistano, sobretudo, a partir da visão de três posses e do gangsta rap. Nesses locais e nesse estilo musical, política e cultura funcionam como verdadeira moeda de troca.

Les réseaux véhiculaires sont passés du stade de simple curiosité pour revêtir aujourd'hui un intérêt certain aussi bien du point de vue de l'industrie automobile que des opérateurs de réseaux et services. Ces réseaux sont en effet une classe émergente de réseaux sans fil permettant des échanges de données entre véhicules ou encore entre véhicules et infrastructure. Ils suscitent un intérêt certain aussi bien en Europe qu’au Japon et en Amérique du Nord, dans le but de fournir de nouvelles technologies capables d'améliorer la sécurité et l'efficacité des transports routiers. Suivant cette même vision, nous nous intéressons dans cette thèse aux communications inter-véhicules dans un environnement urbain. Notre objectif est de proposer des solutions de routage ad hoc et de dissémination géolocalisée, adaptées à un environnement ville, répondant à la fois aux exigences et besoins technologiques des cas d'utilisation envisagés (principalement des services d'information et de confort), mais aussi et surtout aux contraintes des communications inter-véhiculaires ad hoc (fragmentation fréquente du réseau, connectivité intermittente, etc…). Notre démarche consiste à prendre en compte un paramètre clé qui influence le bon fonctionnement du réseau ad hoc de véhicules, à savoir la densité du réseau. Dans un premier temps, nous proposons un mécanisme distribué qui permet de caractériser de manière plus fine la densité de trafic d'un tronçon de route entre deux intersections, en fournissant une distribution spatiale des véhicules mobiles sur la voie de circulation. Ensuite, nous proposons un nouveau protocole de routage géographique, qui tire partie des caractéristiques des voies urbaines et qui intègre le mécanisme d'estimation de densité de trafic pour le routage des paquets. Pour finir, et afin de compléter les mécanismes de communication véhiculaire ad hoc (couche réseau) proposés, nous nous intéressons à la dissémination des données. Nous proposons un nouveau mécanisme distribué et ad hoc qui permet d'émuler le fonctionnement d'une infrastructure classique destinée à diffuser localement (au niveau d'une intersection) des paquets de données de manière périodique. Certains aspects de nos solutions sont évalués analytiquement alors que leurs performances sont évaluées par simulation à l'aide de l'outil QNAP, du simulateur QualNet et du modèle de mobilité réaliste VanetMobiSim. / Inter-Vehicle Communication (IVC) is attracting considerable attention from the research community and the automotive industry, where it is beneficial in providing Intelligent Transportation System (ITS) as well as assistant services for drivers and passengers. In this context, Vehicular Networks are emerging as a novel category of wireless networks, spontaneously formed between moving vehicles equipped with wireless interfaces that could have similar or different radio interface technologies, employing short-range to medium-range communication systems. The distinguished characteristics of vehicular networks such as high mobility, potentially large scale, and network partitioning introduce several challenges, which can greatly impact the future deployment of these networks. In this thesis, we focus on inter-vehicle communication in urban environments. Our main goal is to propose new routing and dissemination algorithms, which efficiently adapts to the vehicular networks characteristics and applications. Temporary disconnection in vehicular network is unavoidable. It is thereby of imminent practical interest to consider the vehicular traffic density. Therefore, at first, we propose a completely distributed and infrastructure–free mechanism for city road density estimation. Then, and based on such traffic information system, we propose a novel intersection-based geographical routing protocol, capable to find robust and optimal routes within urban environments. Finally, in order to help the efficient support of dissemination-based applications, a self-organizing mechanism to emulate a geo-localized virtual infrastructure is proposed, which can be deployed in intersections with an acceptable level of vehicular density. The advocated techniques are evaluated by a combination of network simulation and a microscopic vehicular traffic model.

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Japan is currently undergoing a subtle but pervasive social upheaval, a period of broad structural reform and soul-searching triggered by the rigors of the collapse of the hyperinflated "Bubble Economy" of the late 1980s. As the nation confronts the irretrievable loss of that economic mass delusion, it is turning instead to the reclamation of a quality of life sacrificed for much of the 20th century to national ambition for first military, and then economic pre-eminence. Historian Jeff Kingston has claimed that the ongoing changes, ranging from the reduction of working hours to the institution of freedom of information laws, have been equal in magnitude to those following the Meiji Restoration and Japan's defeat in World War II. Arguably, they represent the long-delayed fruition of postwar democratizing reforms. This dissertation examines the role of American popular music, and particularly hip hop, in reflecting and shaping these changes. Starting with the 1920s and 1930s, when jazz-loving "modern girls" stood for the alluring and threatening decadence of urbanization, the influence of American music on Japan has been strong for decades. This influence came to full flower during and after Japan's surrender and subsequent occupation, as exemplified by successive trends for everything from rockabilly to country and western to folk. Though obviously the condition of occupation enhanced the exchange of musical texts, and did exercise particularly economic pressure on Japanese musicians to adopt American styles, it is not simply a case of cultural adaptation motivated by domination of force. The central testament to this is the eventual role African-American music - not just jazz, but rock, funk, and soul - took on as the 'music of resistance,' initially in connection with the student protests that marked Japan in the 1960's. Such an articulation shows the powerful role of Japanese desire, particularly on the part of youth, for the America represented by popular music. Most recently, hip hop has shown the continued attraction African-American music holds for Japanese people, and youth in particular. Hip hop reached Japan in the early 1980s and entered the mainstream with East End X Yuri's million-selling pop-rap singles of the mid-1990s. Its prominence continues to this day, in many cases embodied in Japanese artists who imitate African-American styles and sounds wholesale. Such imitation has been roundly criticized by international critics and commentators, condemned as contextless cultural theft and a testament to Japanese insensitivity on matters of race. In my study I examine a cadre of contemporary musicians who, while equally dedicated to hip hop, firmly resist such uncritical imitation of blackness, instead emphasizing their own unique musical and cultural innovations. I argue that this transition from imitation to innovation mirrors a broader cultural shift away from widespread deference to authority and towards a greater openness to innovation and change, and is just one way that the work of Japan's underground hip hop artists resonates with the ongoing 'quiet revolution.' Hip hop has encountered a few particularly important ongoing social changes: that from a lifetime employment system to one increasingly characterized by temporary and part-time labor; from a self-declared homogenous society to a multicultural one; and, more generally, from one defined by elite emphasis on social compliance and loyalty to a wider acceptance of iconoclasm and individuality. It is tempting to classify this as the transition from an 'oppressive' system to a 'free' one - from bad to good. But there are complexities and ambivalence inherent in the emergent situation. For example, while the new employment model provides much greater flexibility for individuals and frees them from the past tyranny of the corporate system, it also exposes them to much greater financial uncertainty. The rising sense of self-worth among minorities, for which hip hop is an important channel, simultaneously threatens to transform these identities into objectified fetishes. Individuality is not without its costs. Meanwhile, hip hop is also being deployed in ways that reinforce the old model of deference and authoritarianism, particularly by artists who promote revisionist histories and the revival of militarism. The significance of hip hop for social change derives from a long history of interaction between Japanese and African-American culture. This history resurfaces in hip hop recordings, as well as in the lifestyle of urban musicians and fans. This dissertation follows the daily lives and viewpoints of hip hop artists in Tokyo and throughout Japan, from some of its most successful to those just starting their careers. It tracks their music-making processes and their practices of cultural adaptation, and places them within the larger context of Japanese society. It ultimately describes how an art form derided as imitative and derivative has come to reflect the very unique contours of the new soil to which it has been transplanted.

Many protocols and applications in wireless multi-hop networks indispensably use broad- casting to delivery messages to all nodes in a network. Wireless routing protocols such as DSR, AODV and ODRMP broadcast route discovery messages, and many application protocols exchange query and response messages by broadcasting. Hence, the efficiency of broadcasting is critical to efficiency of these wireless protocols. Efficient wireless broadcast- ing is a topic that this thesis studies where efficiency is measured by the total transmission number to broadcast one unit data to the whole network. The study is done in two ways: extending classical methods and utilizing a novel method, network coding. Classical broadcasting protocols are based on store-and-forward routing that views pack- ets as atomic objects and lets a node store incoming packets in its local queue for some delay, before forwarding one or several copies of the packets to its neighbors. Among the classical broadcast protocols, the simplest and most widely used broadcast protocol is pure flood- ing. Pure flooding reliably provides total coverage of a network, but causes redundancy of packets, resulting in unnecessary collisions, and enormous inefficiency. To combat this inef- ficiency, many efficient broadcast protocols have been studied using probabilistic algorithms such as a gossip protocol, or algorithms based on topology control such as a Multi-Point Relay (MPR) based protocol. These broadcast protocols have been successfully used in many wireless protocols standardized in IEEE 802.11 and IETF. One possible application of the broadcast protocols is wireless mesh networks standard- ized in 802.11Working Group S. The 802.11 mesh networks face challenges such as inefficient broadcasting of so-called associated station information that is partially updated; there ex- ists redundancy between newly updated data and already broadcasted data. This thesis addresses these challenges by introducing an Association Discovery Protocol (ADP) that is combined with MPR-based broadcasting and integrated with an extension of an Optimized Link State Routing (OLSR) protocol for the 802.11 mesh networks. The results of analysis with modeling and simulation show that the protocol effectively decreases control overhead. However, for continuous data traffic, there exists another possible broadcast solution, which could theoretically outperform the broadcast protocols with classical store-and-forward routing and would not require precise topology information. This solution is network coding. Theoretically, network coding enables an optimized solution for wireless broadcasting in a polynomial time, while it is NP-complete with classical store-and-forward routing and only approximation algorithms exist. Hence, broadcasting with network coding is, theoretically, at least as efficient as any other broadcasting. This thesis focuses on utilizing network coding specifically as a practical solution for efficient wireless broadcasting. For the practical solution, this thesis proposes simple al- gorithms based on intuitive rationale about optimal efficiency of wireless network coding. The efficiency of the proposed simple algorithms is theoretically analyzed, and proven to be asymptotically optimal. The efficiency also is experimentally analyzed and shown, in some examples, to outperform other broadcasting with classical store-and-forward routing. Finally, from these simple algorithms we derive a practical broadcasting protocol executing with a simple and efficient coding method (that is, random linear coding). In addition, we propose a simple novel method for real-time decoding that could be combined with the practical network coding broadcasting protocol.

With the rise of First Nations owned and created television content at the turn of the century, came a demand to see an accurate representation of Aboriginality that could look at Aboriginals as both here and modern. From 2003-2006, the first Aboriginal made and produced television series entitled Moccasin Flats, I argue, used modern day hip-hop discourse to both engage and dissect a host of complex issues facing modern day urban Aboriginal society. This research project mobilizes multiple methodologies; including: 1.) Eco’s code and sign function semiotic analysis, which operates to identify various hip-hop codes in the text; 2.)Hall’s method of articulation to look at how meaning is fixed in the discourse surrounding the show; and finally 3) Deleuze’s rhizomic approach to identity to see how the shows main characters are constructed in a way to highlight the paradoxical and undercut certain flirtations with essentialization. This three-tiered methodological process paints a picture of a new complex use of discourse to accentuate different facets of aboriginality that had previously been the sole product of dominant hegemonic institutions which relied on racist stereotypes. By dissecting how identity is formed on Moccasin Flats, I will show how aboriginal filmmakers construct a self-reflexive space where the character is perpetually in the process of ‘becoming’ and identity is always a site of negotiation.

This work examines error rate performance of Multi-Hop communication systems, employing Single Input Single Output (SISO) transmissions over Nakagami-m fading channel. Mobile multi-hop relaying (MMR) system has been adopted in several Broadband Wireless Access Networks (BWAN) as a cost-effective means of extending the coverage and improving the capacity of these wireless networks. In a MMR system, communication between the source node and destination node is achieved through an intermediate node (i.e., Relay Station). It is widely accepted that multi-hop relaying communication can provide higher capacity and can reduce the interference in BWANs. Such claims though have not been quantified. Quantification of such claims is an essential step to justify a better opportunity for wide deployment of relay stations.In this thesis, Bit Error Rate (BER) of multi-hop communication systems has been analysed. Different kinds of fading channels have been used to estimate the error rate performance for wireless transmission. Binary Phase Shift Keying (BPSK) has been employed as the modulation technique and Additive White Gaussian Noise (AWGN) has been used as the channel noise. The same Signal to Noise Ratio (SNR) was used to estimate the channel performance. Three channels were compared by simulating their BER, namely, Rayleigh, Rician and Nakagami. Matlab has been used for simulation.

Wireless sensor network(WSN) is made up of a large number which are deployed in the environment to collect observations. Each sensor node preprocesses and extracts information from the raw observations. Each sensor node also has the ability to communicate with other sensor nodes or a fusion center via wireless channels. Many aspects of WSNs have been investigated recently, such as efficient routing protocols, distributed data compression and transmission, and collaborative signal processing. We investigate the information processing task at the fusion center. Radio transmission is one of the major power consumer, and the required transmission power not linear in distance between the transmitter and the receiver. Hence in this thesis, we consider a decision made at local sensor may need to go through multi- hop for minimal energy consumption. Sensor and relay employed decode and forward protocol. We investigate how to transmission reliability and how to combine the reliability and we proposed a fusion rule when observations are encoded by Turbo code.

This thesis studies the subcarrier power allocation for the relayed signal in Orthogonal Frequency-Division Multiplexing (OFDM) based dual-hop system where the relay node operated in amplify-and-forward (AF) scheme. The investigated system assumes that each subcarrier at the source node transmits the signal with uniform power distribution. Considering the separated sum power constraints which the power constraint at source and relay node are uncorrelated, the conventional iterative water-filling algorithm can maximize the system capacity. However, it requires high computational complexity and the performance improvement is limited when the source node transmits the signal with uniform power distribution, subcarrier power allocation at relay node for capacity maximization is impractical. To further enhance the system performance, a novel subcarrier power allocation method is derived into a closed-form for the relayed signal to minimize the summation of equivalent noise power of the destination node. Comparing with the existing schemes, simulation results demonstrate that the proposed power scaling scheme significantly improves system average bit error rate (ABER).

This report examines Hip Hop performance in Africa –with a focus on Nigeria- and analyzes how questions of race, racial identity, class and nationality feature in the works of African artists. The Nigerian/African artists themselves label their works “African Hip Hop” and they employ the aesthetics of the US and those of their local communities in their performances. Lately however, a couple of Nigerian artists –D’Banj and P Square- troubled the “African” in “African Hip Hop” by performing with popular African American Hip Hop artists, Snoop Dogg and Akon. It was a transnationalistic move that among other issues reflects the fluidity of identity. The performances in the videos of “Mr Endowed Remix” and “Chop My Money” also reflect identity (re)negotiation in postcolonial performances like Hip Hop. African Hip Hop, already, borrows the spectacles of US Hip Hop to express itself to African audiences. However, its collaboration with the US brings it in contact with various sociological issues -such as the conflation of race, class, gender and social mobility- that surround US Hip Hop. This report attempts a close reading of the meeting of “African Hip Hop” and “US Hip Hop” to understand how race, identity, and agency are negotiated in “African Hip Hop” / text