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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Cooperative Networks with Channel Uncertainty / Réseaux coopératifs avec incertitude du canal

Behboodi, Arash 13 June 2012 (has links)
Dans cette thèse, les réseaux coopératifs sont étudiés sous cette hypothèse que la source est incertain par rapport le canal en opération. Dans le premier chapitre, des stratégies coopératives sont développées pour les canaux à relais simultanés (SRC) lesquelles se composent d'un ensemble de deux canaux à relais parmi lesquels le canal en opération est choisi. Cela est équivalent au canal de diffusion à relais (BRC). Les bornes sur la région de capacité de BRC général sont dérivées. Les résultats de capacité sont obtenus pour les cas particuliers du canal à relais simultané semi-dégradé et dégradé Gaussien. Dans le deuxième chapitre, le canal à relais composite est considéré où le canal est tiré aléatoirement d'un ensemble de la distribution conditionnelle. Le débit est fixé en dépit du canal actuel et la probabilité d'erreur (EP) asymptotique est caractérisée. Une nouvelle stratégie de codage sélectif (SCS) est introduit permettant aux relais de choisir -selon leur mesurage du canal – la meilleur schéma de codage entre Décoder-et-Transmettre (DF) et Comprimer-et-Transmettre (CF). Les théorèmes de codage de réseau bruit généralisées sont démontrés pour le cas de réseau unicast général où les relais utilisent soit DF soit CF. Dans le troisième chapitre, le spectre asymptotique de EP est introduit en tant que nouvelle mesure de performance pour réseaux composites. Il est démontré que chaque code avec le débit hors de la borne cut-set, abouti à EP égal à un et le spectre asymptotique de EP coïncide avec la probabilité d'outage pour les réseaux satisfaisant la converse forte. / In this thesis, cooperative networks are studied under the assumption that the source is uncertain about the channel in operation. In the first chapter, cooperative strategies are developed for simultaneous relay channels (SRC) which consist of a set of two single relay channels out of which the channel in operation is chosen. This is equivalent to the broadcast relay channel (BRC). Bounds on the capacity region of the general BRC with two helper relays are derived. Capacity results are obtained for specific cases of semi-degraded and degraded Gaussian simultaneous relay channels. In the second chapter, the composite relay channel is considered where the channel is randomly drawn from a set of conditional distributions according to a given distribution. The transmission rate is fixed regardless of the current channel and the asymptotic error probability (EP) is characterized. A novel selective coding strategy (SCS) is introduced which enables relays to select –based on their channel measurement– the best coding scheme between Compress-and-Forward (CF) and Decode-and-Forward (DF). Generalized Noisy Network Coding theorems are shown for the case of unicast general networks where the relays use either DF or CF scheme. In the third chapter, the asymptotic behavior of EP is studied for composite multiterminal networks. The asymptotic spectrum of EP is introduced as a novel performance measure for composite networks. It is shown that every code with rate outside cut-set bound, yields EP equal to one and for the networks satisfying strong converse condition, the asymptotic spectrum of EP coincides with the outage probability.
492

Black and Blue and Read All Over: News Framing and the Coverage of Crime

Cosand, Kalistah Quilla 20 May 2014 (has links)
This study explores the representation of crime in the news in relation to expressed emotion and intention for future action. Episodic and thematic framing (Iyengar, 1991) and narrative processing (Singer & Bluck, 2001) served as the theoretical foundations of this study and helped examine how scripted news stories involving crime influence levels of fear, anger, and empathy in individuals, and how these emotions subsequently affect behaviors. To measure these framing effects, an experimental manipulation was employed using three conceptually different news stories all involving gun-related crimes. One news story utilized an episodic format, while the other two stories used a thematic format (one positive and one negative). Emotional responses, levels of narrative engagement, policy support, perceived risk of victimization, and pro-social behavioral intentions were measured, all based on exposure to the specific type of news frame. The results of this study indicated that while types of news frames did not have a direct effect on readers' emotions, there was a significant relationship between emotions and future actions. For example, fear, anger, and empathy were significant predictors of perceived risk of victimization, policy support, and pro-social behavioral intentions, respectively. These findings contribute to the understanding of the role emotions play in predicting behavior, both within and beyond the scope of message framing.
493

In Media Res

Sisk, Christopher Andrew 01 January 2018 (has links)
We are inundated by a constant feed of media that responds and adapts in real time to the impulses of our psyches and the dimensions of our devices. Beneath the surface, this stream of information is directed by hidden, automated controls and steered by political agendas. The transmission of information has evolved into a spiral of entropy, and the boundaries between author, content, platform, and receiver have blurred. This reductive space of responsive media is a catalyst for immense political and cultural change, causing us to question our notions of authority, truth, and reality.
494

Un protocole de diffusion des messages dans les réseaux véhiculaires

Ahizoune, Ahmed A. 04 1900 (has links)
De nos jours, la voiture est devenue le mode de transport le plus utilisé, mais malheureusement, il est accompagné d’un certain nombre de problèmes (accidents, pollution, embouteillages, etc.), qui vont aller en s’aggravant avec l’augmentation prévue du nombre de voitures particulières, malgré les efforts très importants mis en œuvre pour tenter de les réduire ; le nombre de morts sur les routes demeure très important. Les réseaux sans fil de véhicules, appelés VANET, qui consistent de plusieurs véhicules mobiles sans infrastructure préexistante pour communiquer, font actuellement l’objet d'une attention accrue de la part des constructeurs et des chercheurs, afin d’améliorer la sécurité sur les routes ou encore les aides proposées aux conducteurs. Par exemple, ils peuvent avertir d’autres automobilistes que les routes sont glissantes ou qu’un accident vient de se produire. Dans VANET, les protocoles de diffusion (broadcast) jouent un rôle très important par rapport aux messages unicast, car ils sont conçus pour transmettre des messages de sécurité importants à tous les nœuds. Ces protocoles de diffusion ne sont pas fiables et ils souffrent de plusieurs problèmes, à savoir : (1) Tempête de diffusion (broadcast storm) ; (2) Nœud caché (hidden node) ; (3) Échec de la transmission. Ces problèmes doivent être résolus afin de fournir une diffusion fiable et rapide. L’objectif de notre recherche est de résoudre certains de ces problèmes, tout en assurant le meilleur compromis entre fiabilité, délai garanti, et débit garanti (Qualité de Service : QdS). Le travail de recherche de ce mémoire a porté sur le développement d’une nouvelle technique qui peut être utilisée pour gérer le droit d’accès aux médias (protocole de gestion des émissions), la gestion de grappe (cluster) et la communication. Ce protocole intègre l'approche de gestion centralisée des grappes stables et la transmission des données. Dans cette technique, le temps est divisé en cycles, chaque cycle est partagé entre les canaux de service et de contrôle, et divisé en deux parties. La première partie s’appuie sur TDMA (Time Division Multiple Access). La deuxième partie s’appuie sur CSMA/CA (Carrier Sense Multiple Access / Collision Avoidance) pour gérer l’accès au medium. En outre, notre protocole ajuste d’une manière adaptative le temps consommé dans la diffusion des messages de sécurité, ce qui permettra une amélioration de la capacité des canaux. Il est implanté dans la couche MAC (Medium Access Control), centralisé dans les têtes de grappes (CH, cluster-head) qui s’adaptent continuellement à la dynamique des véhicules. Ainsi, l’utilisation de ce protocole centralisé nous assure une consommation efficace d’intervalles de temps pour le nombre exact de véhicules actifs, y compris les nœuds/véhicules cachés; notre protocole assure également un délai limité pour les applications de sécurité, afin d’accéder au canal de communication, et il permet aussi de réduire le surplus (overhead) à l’aide d’une propagation dirigée de diffusion. / Nowadays, the car has become the most popular mode of transport, but unfortunately its use is accompanied by a number of problems (accidents, pollution, congestion, etc.). These problems will get worse with the increase in the number of passenger cars, despite very significant efforts made to reduce the number of road deaths, which is still very high. Wireless networks for vehicles called VANET (Vehicle Ad Hoc Networks), were developed when it became possible to connect several mobile vehicles without relying on pre existing communication infrastructures. These networks have currently become the subject of increased attention from manufacturers and researchers, due to their potential for improving road safety and/or offering assistance to drivers. They can, for example, alert other drivers that roads are slippery or that an accident has just occurred. In VANETs, broadcast protocols play a very important role compared to unicast protocols, since they are designed to communicate important safety messages to all nodes. Existing broadcast protocols are not reliable and suffer from several problems: (1) broadcast storms, (2) hidden nodes, and (3) transmission failures. These problems must solved if VANETs are to become reliable and able to disseminate messages rapidly. The aim of our research is to solve some of these problems while ensuring the best compromise among reliability, guaranteed transmission times and bandwidth (Quality of Service: QoS). The research in this thesis focuses on developing a new technique for managing medium access. This protocol incorporates the centralized management approach involving stable clusters. In this technique, time is divided into cycles; with each cycle being shared among the control and service channels, and is divided into two segments. The first is based on TDMA (Time Division Multiple Access) while the second is based on CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) to manage access to the medium. Furthermore, our protocol adaptively adjusts the time consumed in broadcasting safety messages, thereby improving channel capacity. It is implemented in the MAC (Medium Access Control), and centralized in stable cluster heads that are able to adapt to the dynamics of vehicles. This protocol provides a centralized and efficient use of time intervals for an exact number of active vehicles, including hidden nodes/vehicles. Our protocol also provides time intervals dedicated to security applications for providing access to communication channels, and also reduces overhead via directed diffusion of data. Keywords: Ad-hoc networks, VANET, Vehicle, Periodic Safety Messages, broadcast protocols, contention-free.
495

A CASE FOR EMPATHY: IMMIGRATION IN SPANISH CONTEMPORARY MEDIA, MUSIC, FILM, AND NOVELS

Icleanu, Constantin C. 01 January 2017 (has links)
This dissertation analyzes the representations of immigrants from North Africa, Latin America, and Eastern Europe in Spain. As engaged scholarship, it seeks to better the portrayal of immigrants in the mass media through the study of literature, film, and music about immigration spanning from the year 2000 to 2016. Because misconceptions continue to propagate in the media, this dissertation works to counteract anti-immigrant, xenophobic representations as well as balance out overly positive and orientalized portrayal of immigrants with a call to recognize immigrants as human beings who deserve the same respect, dignity, and rights as any other citizen. Chapter 1 examines and analyzes the background to immigration in Spain by covering demographics, the mass media, and political theories related to immigration. Chapter 2 analyzes Spanish music about immigration through Richard Rorty’s social theory of ‘sentimental education’ as a meaningful way to redescribe marginalized minorities as full persons worthy of rights and dignity. Chapter 3 investigates the representation of immigrants in Spanish filmic shorts and cinema. Lastly, Chapter 4 demonstrates how literary portrayals of immigrants written by undocumented immigrants can give rise to strong characters that avoid victimization and rear empathy in their readers in order to affect a social change that minimizes cruelty.
496

考慮時間價值的兩階段群組訊息網路編碼的散播機制 / A two-phase network coding design for mobile time-valued group-message dissemination

劉亭侁, Liu, Ting Shen Unknown Date (has links)
現今因無線通訊技術的進步,使得人們能方便地利用智慧型裝置透過3G,4G和Wi-Fi等技術彼此溝通聊天。其中,聊天應用是最受智慧型裝置使用者歡迎的應用程式。大部分的聊天應用程式需依賴網路以達到訊息交換的目的。然而網路的頻寬是非常有限的,當使用者處在擁擠的環境中時,他們可能會面臨資源耗盡問題。此外,例如在漫遊的情況下有些使用者並沒有行動網路的存取,導致使用者無法使用聊天應用。 因此我們希望利用無線廣播傳輸的特性,開發一個應用於間歇性網路連接的聊天應用程式。然而,廣播傳輸的散播策略若沒有設計得宜,可能導致廣播風暴的問題,使得整體網路效能低落。我們研究的目標是要如何在間歇性網路增加訊息的傳輸效率。為了達成此目標,在我們的研究中考量了許多技術要求,如:訊息具有截止時間與優先權特性、多聊天室應用、傳輸效率。 我們提出了一種兩階段基於網絡編碼設計的訊息散播方法,實現在機會性社群網路中的訊息散播。網絡編碼階段,提高網路頻寬的傳輸效率,也能增加網路傳輸的可靠性;預熱階段能提升網路編碼訊息被解開的機率。最後,利用政大的真實軌跡紀錄評估我們所設計的訊息傳播方法。結果顯示,我們的方法是有效率且優於氾濫式的路由協議和一般的網絡編碼散播技術。 / Nowadays, the advancement of wireless communication technology has allowed people to use smart phones to communicate with each other more easily via 3G/4G, Wi-Fi, etc. One kind of popular mobile Apps is “chat” App. Most chat Apps rely on the Internet to exchange the messages. However, the bandwidth of network is limited in some circumstances. When users stay in the crowded environment, they will face the resource depletion problem. Besides, some people may not subscribe to any cellular network access, e.g. in roaming scenarios. Therefore, we want to develop a novel mobile Chat APP in intermittently connected networks. We utilize the characteristic of the wireless broadcast transmission. However, it may cause the broadcast storm problem without careful design. How to increase the efficiency of message delivery in such intermittently connected networks is our research goal. To achieve this, technical issues in our research involve message priority, multi-chatroom, deadline and transmission efficiency. We proposed a two-phase network coding design for message dissemination to enable the multi-hop instant messaging in Opportunistic Mobile Social Networks. The network coding phase can increase the bandwidth utility and transmission efficiency. Moreover, it can improve transmission robustness and adaptability. The warm up phase can increase the decoding probability of coded packets. Finally, we evaluated our approach with real trace data from NCCU. The results showed that our approach is effective and superior to the flooding based routing protocol and the pure network coding technique.
497

Géopolitique et discours des télévisions d'information arabe par satellite de la 1ère guerre du Golfe à l'occupation de l'Irak (1991-2003) / The Arab News Satellite Channels. Geopolitics and discourse, from the first Golf War to the Iraq's occupation (1991-2003)

Howayek, Hayat 11 October 2011 (has links)
Le phénomène des télévisions satellitaires a fait son apparition dans le monde arabe en 1990-1991. Date de l’instauration du Nouvel Ordre Mondial. Une progression foisonnante s’est produite, par la suite, profitant d’un espace géolinguistique étendu, d’une ouverture sans précédent et d’un financement généreux. Sont-elles l’expression d’un changement ou bien celle d’une adaptation ? Et au service de qui ? L’étude des chaines d’information en continu Al Jazeera, Al Arabiya ou « flexibles », Abou Dhabi et Al Manar est particulièrement intéressante pour répondre à cette question. Comprendre le fond de ce phénomène, les intérêts qu’il représente, qu’il sert, et les limites du changement qu’il est capable de produire, exige de dresser un état des lieux panoramique, une étude de la géopolitique qui a donné lieu à la naissance de ces télévisions, et qui a dicté les évolutions qu’elles ont subit. L’analyse du contenu et du discours vient repérer les expressions d’une culture démocratique, ou anti démocratique, dont dépend la nature du changement / Since 1990-1991, the number of satellite channels and viewers has grown exponentially in the Arab world, taking advantage of a geolinguistic space that afforded unprecedented degree of openness in a field previously dominated by t ightly-controlled state-owned television stations. The date also coincides with the inception of the New World Order, the waging of the first Gulf War which established a new regional order, and the stirrings of the society of communication. This study of news channels (Al Jazeera, Al Arabiya) and “flexible” channels such as (Abu Dhabi and Al Manar), aims to examine whether they are an expression of change or adaption and whether they serve to perpetuate the status quo of the powers that fund them.
498

Un protocole de diffusion des messages dans les réseaux véhiculaires

Ahizoune, Ahmed A. 04 1900 (has links)
No description available.
499

Minority Representations in Crime Drama: An Examination of Roles, Identity, and Power

Chatelain, Megan E. 01 January 2020 (has links)
The storytelling ability of television can be observed in any genre. Crime drama offers a unique perspective because victims and offenders change every episode increasing stereotypes with each new character. In other words, the more victims and criminals observed by the audience, the more likely the show creates the perception of a mean world. Based on previous literature, three questions emerged which this study focused on by asking the extent of Criminal Minds’ ability to portray crime accurately compared to the Federal Bureau of Investigations Uniform Crime Report (UCR) and the Behavioral Analysis Unit’s (BAU-4) report on serial murderers and how those portrayals changed over the fifteen years of the show. A content analysis was conducted through the lens of cultivation theory, coding 324 episodes which produced a sample size of 354 different cases to answer the research questions. Two additional coders focused on the first, middle, and last episodes of each season (N=45) for reliability. The key findings are low levels of realism with the UCR and high levels of realism with the BAU-4 statistics. Mean-world syndrome was found to be highly likely to be cultivated in heavy viewers. Finally, roles for minority groups did improve overtime for Black and Brown bodies, yet Asian bodies saw a very small increase in representation. LGBT members were nearly nonexistent. The findings indicated that there is still not enough space in television for minority roles and found that the show perpetuated stereotypes. Additional implications and themes include a lack discourse on violence and erasure of sexual assault victims.
500

Women's Professional Sports: A Case Study on Practices that Could Increase Their Profitability

McArdle, Danielle H 01 January 2016 (has links)
Women’s professional sports leagues have often been considered a risky business endeavor. Critics cite low attendance, lack of sponsorships, lack of media rights deals, and numerous other reasons for why women’s professional sports leagues are not profitable. In analyzing the current landscape of women’s professional sport leagues, this paper uses a case study approach to develop a strategy that will highlight lessons learned from past women’s professional sports leagues, current professional sports leagues, sponsorship agreements, fans, social, digital, and mobile marketing strategies, and management practices to show how the business of women’s sports could be made into a more profitable endeavor.

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