abstract: Diffusion processes in networks can be used to model many real-world processes, such as the propagation of a rumor on social networks and cascading failures on power networks. Analysis of diffusion processes in networks can help us answer important questions such as the role and the importance of each node in the network for spreading the diffusion and how to top or contain a cascading failure in the network. This dissertation consists of three parts. In the first part, we study the problem of locating multiple diffusion sources in networks under the Susceptible-Infected-Recovered (SIR) model. Given a complete snapshot of the network, we developed a sample-path-based algorithm, named clustering and localization, and proved that for regular trees, the estimators produced by the proposed algorithm are within a constant distance from the real sources with a high probability. Then, we considered the case in which only a partial snapshot is observed and proposed a new algorithm, named Optimal-Jordan-Cover (OJC). The algorithm first extracts a subgraph using a candidate selection algorithm that selects source candidates based on the number of observed infected nodes in their neighborhoods. Then, in the extracted subgraph, OJC finds a set of nodes that "cover" all observed infected nodes with the minimum radius. The set of nodes is called the Jordan cover, and is regarded as the set of diffusion sources. We proved that OJC can locate all sources with probability one asymptotically with partial observations in the Erdos-Renyi (ER) random graph. Multiple experiments on different networks were done, which show our algorithms outperform others. In the second part, we tackle the problem of reconstructing the diffusion history from partial observations. We formulated the diffusion history reconstruction problem as a maximum a posteriori (MAP) problem and proved the problem is NP hard. Then we proposed a step-by- step reconstruction algorithm, which can always produce a diffusion history that is consistent with the partial observations. Our experimental results based on synthetic and real networks show that the algorithm significantly outperforms some existing methods. In the third part, we consider the problem of improving the robustness of an interdependent network by rewiring a small number of links during a cascading attack. We formulated the problem as a Markov decision process (MDP) problem. While the problem is NP-hard, we developed an effective and efficient algorithm, RealWire, to robustify the network and to mitigate the damage during the attack. Extensive experimental results show that our algorithm outperforms other algorithms on most of the robustness metrics. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2018

Seminario de investigación para optar al grado de licenciado en comunicación social / 1990. Muchas cosas pasaban. Chile recuperaba la democracia y un nuevo país se estaba tejiendo. Es un período frágil, y como un niño debe protegerse de cualquier exposición al riesgo. El futuro de la transición política era incierto. Durante los primeros años de la década una serie acciones de mano de fracciones reaccionarias de extrema izquierda estaban desequilibrando el sistema. Capítulos como el asesinato del senador Jaime Guzmán, el secuestro de Cristián Edwards, hijo del dueño de El Mercurio, y la captura de una familia absolutamente corriente en Ñuñoa hacia 1992, funcionaron como ultimátumes al orden y cernieron la amenaza sobre todos los ciudadanos. La paranoia colectiva estaba resquebrajando a la democracia, al niño que tanto costó parir. Y se produce la demonización de la infancia, que es justamente lo que se quiere proteger, al niño como bandera de lo que está naciendo. Xuxa no podía haber llegado en mejor momento. No es casual que la sensual cantante apareciera en plena refundación del país. Ni que sus lúdicos cantos brasileños encarnaran la amenaza en un ambiente de fuerte nacionalismo. Mientras la transición permaneciese en la incubadora, era de vital importancia que se articulara fuertemente en la sociedad el discurso familiar, la protección a la infancia y la condición moral. A partir de la psicosis colectiva todos son posibles sospechosos y la comunidad busca protección. Bajo esa perspectiva, todo lo que signifique control va a estar legitimado por la paranoia ambiente, y eso significa conculcar los derechos civiles. Y nadie se va a negar, los ciudadanos quieren que haya control y entregan a los gobernantes la posibilidad de controlar a cualquier precio.

In the fields of development and public health, the decisions of the rural poor are often treated as simple, unanimous, and driven by cultural preconceptions and beliefs. This is particularly the case for sub-Saharan Africa, where a dehistoricizing tendency presupposes an ontological link between an African culture and its tendency to interpret the world through the lens of belief. Generally, household activities are not seen as the kinds of modes of objectifying social practice that are the outcome of complex historical struggles over representation, and pre-disposing cultural factors are presumed to be the key determinants of household behavior. The three papers that constitute this alternative-format, article-based dissertation interrogate these assumptions. Although they address diverse subjects (the rise of West African Pentecostalism; the logic of treatment-seeking behavior in Benin; credit and savings strategies in rural Mali), they share a methodological concern with close analysis of the complexity of household decision-making in the moment, study over time, and attention to local concerns in the context of larger social transformations. In both medical and economic contexts, this approach demonstrates not only that behavior is primarily determined by enabling factors, but that the cultural factors that do condition behavior can be understood as creative, rational, and instructive of larger concerns, rather than merely as an impediment to development goals.

The Internet provides many sources of financial information that investors can use to help with investment decisions and in interpreting companies' accounting information. One source of information is Internet stock message boards such as those at Yahoo! Finance. This source allows for anonymous postings and information exchange. Despite the possibility of the information being incorrect many individuals visit these message boards. The purpose of this study is to investigate Internet stock message boards and address the primary question: From an individual investor perspective, do message boards, which contain accounting information, influence investment decisions? The question is addressed using psychology rumor literature and attitude theories. Message board postings are a type of rumor, since not all the information is verified and is usually intended to persuade a belief or influence a decision. Further, the messages may influence an investor by causing a change in attitude about the investment. Using an experiment, message board influence on an investment decision and attitude was tested. The results indicated that individuals that received negative message board postings did have a significantly higher change in investment amount as compared to a control group that did not receive any message postings. The positive message board group and the control group were not significantly different in their amount of investment change. The results of the study also show that message board postings influenced attitude, those that received negative (positive) postings had a negative (positive) attitude about the investment. It was further found that those with a negative (positive) attitude decreased (increased) their investment. Finally, contrary to expectations, investment experience did not lead to an individual being less influenced by message board postings. This study contributes to the accounting literature by investigating an additional source of Internet financial reporting that may or may not contain correct information. The SEC is concerned over the manipulative opportunities that are available within these message boards and many investors are exploring these new sources of information instead of relying on traditional accounting information. This study finds that negative postings have an influence on investment decision and possibly should be investigated as manipulative techniques.

Nathaniel Hawthorne's The House of the Seven Gables continuously plays with the idea of narrative authority to explore concepts of class and power within the novel. Since these concepts of class and power are also a central focus of Subaltern Studies, applying some of this body of scholarship to the novel brings into focus these concepts and sheds light on the motivations and types of resistance in the novel. The upper class characters, including the Pyncheons, construct and maintain a narrative based on the declarations of professionals and officials of the state and church. It discusses only the most noble characteristics and events of the upper classes and relies solely on rational, empirical thought. They create this narrative to maintain their authority and dominance. The lower classes, including the Maules, construct an alternate narrative to resist the upper class that is collected and passed down through rumor. Supernatural elements like ghosts and curses figure prominently in this narrative. It is only when the Pyncheon and Maule families begin to listen to and validate multiple narratives that class and power become less important and the reconciliation between families happens.

Social media is becoming a popular disclosure channel with higher speed, reach, and extensive network effects. A negative information role of social media is to increase the spread of information disorder defined as false information or truth presented with the intent to harm. This study investigates whether and how auditors react to information disorder on social media, in the context of clients' merger and acquisition (M&A) rumors. I document that information disorder is positively associated with audit fees but not associated with audit delay and the likelihood of audit resignations. Additionally, increased social media attention can elevate the level of risk associated with rumors. I therefore predict that the associations will be more pronounced with greater social media influence. Using a manually collected Twitter rumor subsample, I find mixed results. This dissertation contributes to the auditing literature by documenting how external auditors incorporate social media-induced information disorder into client retention and pricing decisions.

张楠迪扬. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 140-157) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / Zhang Nan Diyang.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-09-26T16:18:24Z No. of bitstreams: 1 Micael Vier Behs_.pdf: 3421843 bytes, checksum: 36f4165a69ed74d69d2c8fccf9a6aa91 (MD5) / Made available in DSpace on 2017-09-26T16:18:24Z (GMT). No. of bitstreams: 1 Micael Vier Behs_.pdf: 3421843 bytes, checksum: 36f4165a69ed74d69d2c8fccf9a6aa91 (MD5) Previous issue date: 2017-06-16 / Nenhuma / Essa tese está organizada em torno de um diagrama que relaciona três instâncias semiotécnicas – a página Guarujá Alerta no Facebook, o site jornalístico Folha.com e suas respectivas seções de comentários. Observamos e inferimos as construções de sentido quando essas instâncias estão em interações em torno do boato da Bruxa de Guarujá (2014). A perspectiva são as epistemologias da midiatização, em específico quando se abordam as redes digitais. A construção do caso acadêmico é um processo que relaciona aporte metodológico, inferências criativas e existenciais, analogias circulares e a definição de três proposições de pesquisa. A primeira delas sugere que as construções de sentido em torno do caso se desdobram a partir de interações entre os três meios em análise, em contato com meios tangenciais, dada a natureza relacional do ambiente midiático. A segunda proposição indica que a página e o site desenvolvem estratégias distintas de acesso dos interagentes ao seu sistema, situação que desencadeia experiências autorregulatórias, assim como contendas entre produção e recepção produtiva. A terceira proposição revela tentativas, manifestadas por atores sociais midiatizados, de encontrar culpados para a exacerbação do boato em morte. Identifica-se um objeto simbólico, denominado de “culpabilização”, que, entretanto, não se apresenta de forma estática e consensual ao longo do caso analisado, ganhando distintos contornos e perspectivas interpretativas a partir de sua associação a outros elementos postos em circulação no mercado discursivo. A análise centra-se nos conceitos de circulação, midiatização, boato, incerteza e disrupção, demonstrando o potencial degenerativo associado ao funcionamento das redes, ainda que delas também verta informação regulatória, reiterando-se o lugar mediador que segue reservado ao jornalismo canônico em tempos de indistinção entre produtores e receptores de meios semiotécnicos. / This dissertation is structured around a diagram that relates three semio-technical media, viz. the Guarujá Alerta Facebbok page, the Folha.com news site, and their respective sections of comments. It makes observations and inferences about the construction of meaning when these media are involved in interactions around the rumor about the so-called “Guarujá Witch” (2014). Its methodological perspective is the concept of mediatization, specifically when discussing digital media. The construction of the academic case is a process that relates methodological contributions, creative and existential inferences, circular analogies and the definition of three research propositions. The first proposition suggests that the constructions of meaning around that case develop based on interactions between the three media analyzed here, which are in contact with tangential media, given the relational nature of the media environment. The second proposition indicates that the Facebook page and the news site employ different strategies to enable web surfers to access their systems, which is a situation that gives rise to self-regulatory devices, as well as conflicts between production and productive reception. The third proposition reveals attempts by mediatized social actors at finding those who were guilty for the culmination of the rumors in a murder. The study identifies a symbolic object called “blaming”, which, however, does not present itself in a static and consensual manner throughout the case analyzed here, but acquires different contours and interpretive perspectives based on its association with other elements that are put into circulation in the discursive market. The analysis focuses on the concepts of circulation, mediatization, rumor, uncertainty and disruption and shows the degenerative potential associated with the way the media function, although the latter also provide regulatory information. This reiterates the mediating place that is still reserved for canonical journalism in a time of non-distinction between producers and receivers of semio-technical media.

Made available in DSpace on 2016-04-26T18:17:12Z (GMT). No. of bitstreams: 1 Valdir Martins.pdf: 613721 bytes, checksum: ae9d14ddb82d356bf7ca6330dbba6591 (MD5) Previous issue date: 2008-05-09 / This PhD thesis aims at the study of the meaning of rumor, defined as a constitutive element of communication with the ability of provoking alterations and influencing the performance of the financial market. It intends to show the changes capitalism has undergone throughout the historical and social evolutions of modern to postmodern civilization, focusing on the mediatization of the relations, and the adaptations and technical employments it has made use of to maintain the acceptance and the renovation of its practices. In our research, the concept of media culture is that of an organization based upon the mediation of social life through instruments of communication developed by new technologies, creating the predominance of the market as the single human universal and its unfoldings in the financial field. We propose a psychosocial analysis of the market and of the rumor as a vital element for its dynamics. The challenge for the research dwells in the fact that, as an unpredictable element in the performance of the financial market, the rumor has never received an appropriate attention, and there has never been a discussion of its importance to the conditioning of the oscillations, above all in the São Paulo Stock Exchange (Bovespa). The main hypothesis of this work is that, as a means of communication, the rumor has a preponderant role in the behavior of agents, directly influencing the performance and the oscillations of indexes, reflecting the capacity of reasoning in the construction of reality and demystifying the presumed rationality of markets. Our goal is to make a conceptual demonstration of the various historical passages and the adaptations of capital in the new infotechnical scenario, with special attention to the aspects of fluidity, liquidity and shallowness of actuality, supported by the dispute between time and space; attention will also be given to the influence of the behavior of participants in the alterations of market movements and to the new condition of the subject in this context of psychological and social changes. As to the approach of this work, we have chosen a theoretical and epistemological reflection. The methodological criteria have been based upon a bibliographical research guided by the concerns of critical analysis. We have also used case analysis, following closely the performance of ibovespa and the dollar, with the intention of revealing its tight connection to market oscillations. The structure of our argumentation has three parts: 1) the evolution of capitalism and its transformations; 2) the construction of market and its diverse traits; 3) the rumor and its function in the financial market. Our theoretical frame of reference is made up of authors such as Kapferer, Allport, Morin, Bauman, Baudrillard, Virilio and Trivinho, among others, and it is based upon the perspectives of the evolution of capitalism with foundation in the State; the construction of market identity; the surpassing of the subject; and the influence of rumor as a structuring component of the behavior of financial markets. This work intends to contribute to a more useful knowledge of the topic of communication in the business world and to bring into discussion the element of indetermination in the markets / A presente Tese de Doutorado se consagra ao estudo da significação do boato, definido como elemento constituinte da comunicação e capaz de provocar alterações e influenciar o desempenho do mercado financeiro. Visa a mostrar as mudanças que sofreu o capitalismo através da evolução histórico-social da civilização moderna para a pós-moderna, com ênfase na midiatização das relações, e as adaptações e os usos de suas técnicas no intuito de se perpetuar pela aceitação e renovação de suas práticas. Para a pesquisa, a noção de cultura midiática equivale a uma organização baseada na intermediação da vida social por instrumentos comunicacionais desenvolvidos pelas novas tecnologias, eclodindo com a predominância do mercado como único universal humano e de seus desdobramentos na área financeira. Faz-se aqui uma abordagem psicossocial do mercado e do boato como elemento vital para sua dinâmica. O problema de pesquisa reside no fato de que, como elemento imprevisível na atuação do mercado financeiro, o boato nunca recebeu tratamento adequado, nem se discutiu sua importância no condicionamento das oscilações, sobretudo na Bolsa de Valores de São Paulo (Bovespa). A principal hipótese de trabalho é a de que, como forma comunicacional, o boato exerce papel preponderante no comportamento dos agentes, influenciando diretamente o desempenho e as oscilações dos indicadores, refletindo a capacidade do pensamento na construção da realidade e desmistificando a suposta racionalidade dos mercados. O objetivo é fazer uma demonstração conceitual das diversas passagens históricas e das adaptações do capital ao novo cenário infotécnico, com especial atenção aos aspectos de fluidez, liquidez e superficialidade da atualidade, sustentados pela disputa entre tempo e espaço, bem como à influência do comportamento dos participantes na alteração dos movimentos mercadológicos e à nova condição do sujeito nesse contexto de mudanças psicológicas e sociais. Como proposta de trabalho, adotamos principalmente uma reflexão teórica e epistemológica. O percurso metodológico baseou-se em pesquisa bibliográfica, norteada pela preocupação de uma análise crítica. Usou-se também o estudo de caso, com o acompanhamento do desempenho do ibovespa e do dólar, para revelar sua ligação umbilical com as oscilações do mercado. A estrutura da argumentação tem três partes: I) a evolução do capitalismo e suas transformações, II) a construção do mercado e suas várias facetas e III) o boato e sua função no mercado financeiro. O quadro teórico de referência é formado por autores como Kapferer, Allport, Morin, Bauman, Debord, Baudrillard, Virilio e Trivinho, entre outros, e se baseia nas perspectivas da evolução do capitalismo alicerçado no Estado, na construção da entidade mercado, na superação do sujeito e na influência do boato como componente estruturante do comportamento do mercado financeiro. A pesquisa pretende concorrer para uma compreensão mais profícua do tema da comunicação no mundo dos negócios e para resgatar o elemento de indeterminação nos mercados

This Thesis expands on the current developments of the theory of stochastic diffusion processes of rumours. This is done by advancing the current mathematical characterisation of the solution to the Daley-Kendall model of the simple S-I-R rumour to a physical solution of the sub-population distribution over time of the generalised simple stochastic spreading process in social situations. After discussing stochastic spreading processes in social situations such as the simple epidemic, the simple rumour, the spread of innovations and ad hoc communications networks, it uses the three sub-population simple rumour to develop the theory for the identification of the exact sub-population distribution over time. This is done by identifying the generalised form of the Laplace Transform Characterisation of the solution to the three sub-population single rumour process and the inverse Laplace Transform of this characterisation. In this discussion the concept of the Inter-Changeability Principle is introduced. The general theory is validated for the three population Daley-Kendall Rumour Model and results for the three, five and seven population Daley-Kendall Rumour Models are pre- sented and discussed. The α - p model results for pseudo-Maki-Thompson Models are presented and discussed. In subsequent discussion it presents for the first time a statement of the Threshold Problem for Stochastic Spreading Processes in Social settings as well as stating the associated Threshold Theorem. It also investigates limiting conditions. Aspects of future research resulting from the extension of the three subpopulation model to more than three subpopulations are discussed at the end of the thesis. The computational demands of applying the theory to more than three subpopulations are restrictive; the size of the total population that can be considered at one time is considerably reduced. To retain the ability to compute a large population size, with an increase in the number of possible subpopulations, a possible method of repeated application of the three population solution is identified. This is done through the medium of two competing mutually exclusive rumours. The final discussion occurs on future investigation into the existence of limit values, zero states, cyclic states and absorbing states for the M subpopulation case. The generalisation and inversion of the Laplace Transform as well as the consequential statement of the threshold theorem, derivation of the transition probabilities and discussion of the limiting conditions are significant advances in the theory of rumours and similar social phenomena. / Thesis (Ph.D.) -- University of Adelaide, School of Mathematical Sciences, 2008