A Scalable Trust Management scheme for Mobile Ad Hoc Networks

Mobile ad hoc networks MANETs, have special resource requirements and different topology features, they establish themselves on fly without reliance on centralized or specialized entities such as base stations. All the nodes must cooperate with each other in order to send packets, forwarding packets, responding to routing messages, sending recommendations, among others, Cooperating nodes must trust each other. In MANETs, an untrustworthy node can wreak considerable damage and adversely affect the quality and reliability of data. Therefore, analyzing the trust level of a node has a positive influence on the confidence with which an entity conducts transactions with that node. This thesis presents a new trust management scheme to assign trust levels for spaces or nodes in ad hoc networks. The scheme emulates the human model which depends on the previous individual experience and on the intercession or recommendation of other spaces in the same radio range. The trust level considers the recommendation of trustworthy neighbors and their own experience. For the recommendation computation, we take into account not only the trust level, but also its accuracy and the relationship maturity. The relationship rationality -maturity-, allows nodes to improve the efficiency of the proposed model for mobile scenarios. We also introduce the Contribution Exchange Protocol (CEP) which allows nodes to exchange Intercessions and recommendation about their neighbors without disseminating the trust information over the entire network. Instead, nodes only need to keep and exchange trust information about nodes within the radio range. Without the need for a global trust knowledge. Different from most related works, this scheme improves scalability by restricting nodes to keep and exchange trust information solely with direct neighbors, that is, neighbors within the radio range. We have developed a simulator, which is specifically designed for this model, in order to evaluate and identify the main characteristics of the proposed system. Simulation results show the correctness of this model in a single-hop network. Extending the analysis to mobile multihop networks, shows the benefits of the maturity relationship concept, i.e. for how long nodes know each other, the maturity parameter can decrease the trust level error up to 50%. The results show the effectiveness of the system and the influence of main parameters in the presence of mobility. At last, we analyze the performance of the CEP protocol and show its scalability. We show that this implementation of CEP can significantly reduce the number messages

On the functions and consequences of the Internet for social movements and voluntary associations

"Voluntary associations are particularly prone to embrace the new Net technologies, because on the basis of these new tools, they are better able to be what they always aspired to be: democratically constituted collectivities relying on a complex interplay between internal and external, vertical and horizontal, upward and downward, informal and formal, bilateral and multilateral communications. As the most flexible, adaptive of all media - the Internet has very different functions and consequences under different environmental conditions, so that it can be fitted into almost existing socio-cultural settings and is more likely to consolidate and strengthen them than to act as a causal agent of change. Likewise, the conclusion is warranted that primary face to face interactions as well as conventional mass media communications will not become obsolete with expanding computer-supported interactions. On the contrary, they may have to be expanded and intensified before the full potentials of online communication can be exploited." (author's abstract)Der vorliegende Beitrag untersucht die Funktionen und Konsequenzen des Internet für soziale Bewegungen und Freiwilligen-Vereinigungen. Beide neigen besonders dazu, die neuen Netztechnologien zu verwenden, da sie die Grundlage dafür bilden, dass die Gruppen leichter in der Lage sind, das zu sein, was schon immer angestrebt wurde, nämlich demokratisch konstituierte Gemeinschaften, die auf eine komplexe wechselseitige Beziehung zwischen interner und externer, vertikaler und horizontaler, informeller und formeller, bilateraler und multilateraler Kommunikation aufbauen. Als das flexibelste aller Medien bietet das Internet viele verschiedene Funktionen und Konsequenzen, so dass es in fast alle soziokulturellen Zusammenhänge passt und diese eher stärken und konsolidieren kann anstatt die Ursache für deren Wandel zu sein. Es wird geschlussfolgert, dass weder die Kommunikation von Angesicht zu Angesicht noch die konventionelle massenmediale Kommunikation durch die expandierenden computergestützten Interaktionen obsolet wird. Ganz im Gegenteil, zunächst müssen diese expandieren und intensiviert werden, um das ganze Potential der Online-Kommunikation nutzen zu können. (ICDÜbers

THE SURVIVAL AND DEVELOPMENT OF CHINESE NEW MEDIA BUSINESS: AMONG STATE, MARKET, AND PUBLIC

Master'sMASTER OF ART

Smart Wireless Sensor Networks

The recent development of communication and sensor technology results in the growth of a new attractive and challenging area - wireless sensor networks (WSNs). A wireless sensor network which consists of a large number of sensor nodes is deployed in environmental fields to serve various applications. Facilitated with the ability of wireless communication and intelligent computation, these nodes become smart sensors which do not only perceive ambient physical parameters but also be able to process information, cooperate with each other and self-organize into the network. These new features assist the sensor nodes as well as the network to operate more efficiently in terms of both data acquisition and energy consumption. Special purposes of the applications require design and operation of WSNs different from conventional networks such as the internet. The network design must take into account of the objectives of specific applications. The nature of deployed environment must be considered. The limited of sensor nodes� resources such as memory, computational ability, communication bandwidth and energy source are the challenges in network design. A smart wireless sensor network must be able to deal with these constraints as well as to guarantee the connectivity, coverage, reliability and security of network's operation for a maximized lifetime. This book discusses various aspects of designing such smart wireless sensor networks. Main topics includes: design methodologies, network protocols and algorithms, quality of service management, coverage optimization, time synchronization and security techniques for sensor networks

The Future of Reputation: Gossip, Rumor, and Privacy on the Internet

This is the complete text of Daniel J. Solove\u27s book, THE FUTURE OF REPUTATION: GOSSIP, RUMOR, AND PRIVACY ON THE INTERNET (Full Text) (Yale University Press, October 2007).Teeming with chatrooms, online discussion groups, and blogs, the Internet offers previously unimagined opportunities for personal expression and communication. But there\u27s a dark side to the story. A trail of information fragments about us is forever preserved on the Internet, instantly available in a Google search. A permanent chronicle of our private lives - often of dubious reliability and sometimes totally false - will follow us wherever we go, accessible to friends, strangers, dates, employers, neighbors, relatives, and anyone else who cares to look. This engrossing book, brimming with stories of gossip, slander, and rumor on the Internet, explores the profound implications of the online collision between free speech and privacy.Solove explores how the Internet is transforming gossip, the way we shame others, and our ability to protect our own reputations. Focusing on blogs, Internet communities, cyber mobs, and other current trends, he shows that, ironically, the unconstrained flow of information on the Internet may impede opportunities for self-development and freedom. Longstanding notions of privacy need review: unless we establish a balance among privacy, free speech, and anonymity, we may discover that the freedom of the Internet makes us less free

Game Theory Based Privacy Protection for Context-Aware Services

In the era of context-aware services, users are enjoying remarkable services based on data collected from a multitude of users. To receive services, they are at risk of leaking private information from adversaries possibly eavesdropping on the data and/or the un--trusted service platform selling off its data. Malicious adversaries may use leaked information to violate users\u27 privacy in unpredictable ways. To protect users\u27 privacy, many algorithms are proposed to protect users\u27 sensitive information by adding noise, thus causing context-aware service quality loss. Game theory has been utilized as a powerful tool to balance the tradeoff between privacy protection level and service quality. However, most of the existing schemes fail to depict the mutual relationship between any two parties involved: user, platform, and adversary. There is also an oversight to formulate the interaction occurring between multiple users, as well as the interaction between any two attributes. To solve these issues, this dissertation firstly proposes a three-party game framework to formulate the mutual interaction between three parties and study the optimal privacy protection level for context-aware services, thus optimize the service quality. Next, this dissertation extends the framework to a multi-user scenario and proposes a two-layer three-party game framework. This makes the proposed framework more realistic by further exploring the interaction, not only between different parties, but also between users. Finally, we focus on analyzing the impact of long-term time-serial data and the active actions of the platform and adversary. To achieve this objective, we design a three-party Stackelberg game model to help the user to decide whether to update information and the granularity of updated information

Social informatics

5th International Conference, SocInfo 2013, Kyoto, Japan, November 25-27, 2013, Proceedings</p

Beyond the flagship: politics & transatlantic trade in American department stores, 1900-1945

Historians have long viewed American department stores as barometers of social change, anchors of modern urban life, and purveyors of a new kind of consumer capitalist culture. In its heyday, from the late nineteenth century to the middle twentieth century, the department store was all of these things, but it was also much more. This dissertation draws on business, government, and family papers to reveal how a new kind of businessman, the department store retailer, pioneered powerful political and trade networks that were deeply embedded in Washington and stretched across the Atlantic into the increasingly volatile capitals of Europe. As campaign contributors, trade policy advisors, and political appointees, retailers like John Wanamaker, Isidor Straus, Louis Kirstein, and Ira Hirschmann regularly moved through the inner circles of the national government. They could just as easily be found on Capitol Hill, or at trade offices located in London or Paris, as behind their own desks in the upper floors of Wanamaker’s or Filene’s. Retailers’ command of vast transatlantic trade networks, now largely forgotten, made them key participants in pressing debates about everything from tariff reform and economic recovery to wartime mobilization and the plight of refugees. Yet retailers approached politics and commerce with profoundly different sensibilities than executives at other major American corporations, such as Ford, United Fruit, or Coca Cola. In the retail industry, commercial expansion depended not on the domination of foreign markets and foreign workers, but rather on transnational cooperation and the development of policies and business methods that upheld both the sovereignty and distinctiveness of other nations—and their goods. In this complex era, as the imperatives of trade routinely collided with politics and other large forces, from devastating world wars and widespread depression to the rise of new radical ideologies, retailers did much more than market desire. They brokered vital connections between Americans, Washington, and the world