48 research outputs found

    Spectrum Sensing and Mitigation of Primary User Emulation Attack in Cognitive Radio

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    The overwhelming growth of wireless communication has led to spectrum shortage issues. In recent days, cognitive radio (CR) has risen as a complete solution for the issue. It is an artificial intelligence-based radio which is capable of finding the free spectrum and utilises it by adapting itself to the environment. Hence, searching of the free spectrum becomes the key task of the cognitive radio termed as spectrum sensing. Some malicious users disrupt the decision-making ability of the cognitive radio. Proper selection of the spectrum scheme and decision-making capability of the cognitive reduces the chance of colliding with the primary user. This chapter discusses the suitable spectrum sensing scheme for low noise environment and a trilayered solution to mitigate the primary user emulation attack (PUEA) in the physical layer of the cognitive radio. The tag is generated in three ways. Sequences were generated using DNA and chaotic algorithm. These sequences are then used as the initial seed value for the generation of gold codes. The output of the generator is considered as the authentication tag. This tag is used to identify the malicious user, thereby PUEA is mitigated. Threat-free environment enables the cognitive radio to come up with a precise decision about the spectrum holes

    Prevention of Emulation Attack in Cognitive Radio Networks Using Integrated Authentication

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    Security is the prominent problem in emerging cognitive radio. Protecting the chief user’s and sub-ordinate user’s right to use the spectrum results in the correct cognitive radio operation. The major user emulation attack is a physical layer attack which disrupts the secondary user’s operation. An Advanced Encryption Standard scheme is used in this work that aims to defeat the chief User Emulation Attack by the correct detection of the chief user. The reference signal is encrypted and transmitted along with the Digital TV signal. Using a shared secret the receiver regenerates the reference and the cross association and the auto correlation are calculated which helps in the accurate detection of the chief user as well as the malicious user. The simulations were carried out and the results show that the detection scheme results in zero misdetection and also false alarm which is below a set threshold

    A Robust Cooperative Spectrum Sensing-Assisted Multiuser Resource Allocation Scheme

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    Cognitive radio (CR), which is proposed as a solution for spectrum scarcity, imposes some threats to the network. One severe attack to cognitive radio network is the primary user emulation attack (PUEA), in which an attacker may transmit its signal with high power or mimic specific features of the primary user's signal to prevent secondary users from accessing the licensed spectrum. In this paper, we study a subcarrier and power allocation problem for orthogonal frequency division multiple access-(OFDMA-) based CR systems in the presence of PUEA. To maximize the system throughput while keeping the interference introduced to the primary user (PU) below given thresholds with a certain probability, a joint design of a robust cooperative spectrum sensing and a resource allocation scheme is proposed. In the proposed scheme, the inaccurate classification of PU signals and PUEA signals provided by robust cooperative spectrum sensing is utilized by resource scheduling module. To further exploit the underutilized spectrum bands, we also evaluate the performance of the proposed scheme in the hybrid overlay/underlay spectrum access mechanism. Numerical results demonstrate the effectiveness of the proposed scheme compared to conventional scheme regardless of the number of SUs or the kind of spectrum access mechanism being used

    Semantic discovery and reuse of business process patterns

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    Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse

    The Media in the Network Society: Browsing, News, Filters and Citizenship

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    560 p. : ill. ; 23 cm.Libro ElectrónicoIn the Network Society the development of a new communicational model has been taking shape. A communicational model characterized by the fusion of interpersonal communication and mass communication, connecting audiences and broadcasters under a hypertextual matrix linking several media devices. The Networked Communication model is the informational societies communication model. A model that must be understood also in its needed literacies for building our media diets, media matrixes and on how it’s changing the way autonomy is managed and citizenship exercised in the Information Age. In this book Gustavo Cardoso develops an analysis that, focusing on the last decade, takes us from Europe to North America and from South America to Asia, combining under the framework of the Network Society a broad range of scientific perspectives from Media Studies to Political Science and Social Movements theory to Sociology of Communication.Index of Figures Index of Tables Preface Acknowledgements The Media in the Network Society. Contextualizing the Media in the Network Society; Media, Autonomy and Citizenship 1. The Multiple Dimensions of the Network Society. The Network Society; The Culture of the Informational Societies 2. Societies in Transition to the Network Society. Societies in Transition in the Global Network; Societies in Transitions, Values and Social Well-Being; Media and Social Change in the Network Societies 3. From Mass to Networked Communication: Communicational Models and the Informational Society Communicational Models and the Informational Society. Communicational Globalization in the 20th Century; Mass Media and New Media: the Articulation of a New Communicational Model?; Rhetoric, Accessibility of Information and Narratives Networked Communication 4. A Constellation of Networks: Mass Media, Games, Internet and Telephones. An Entertainment Meta-System in Transition: from Multimedia Games to Television; The New Entertainment Player: Multimedia Games; The Reaffirmation of TV as a Central Element of the Entertainment Meta-System; From Interactive Television to Networked Television 5. Has the Internet Really Changed the Mass Media?. From the End of Journalism to Its Reconstruction; The Information Meta-System and Its Network Organization; Television: the New Online Functions; From Radio Interactivity to Newspaper; Time Management: the Media Network 6. The Massification of the Internet Experience. The New Frontiers and Their Entry Portals; Media, Memory and Filters 7. Media and Citizenship in the Network Society. Mediation of Citizenship and Informational Literacy; The Different Media Ages; Different Media Ages, Different Forms of Citizenship? 8. Mediated Politics: Citizens and Political Parties in Continuous Democracy; An Institutional and Parliamentary; Framework for Continuous Democracy; The Internet as Hostage of Institutional Informational Politics? 9. Media, Mobilization and Protests. Goku vs. The Ministry of Culture: Terràvista, Television and Newspapers; The Closure of RTP2: Television Seen from the Internet; The Pro-East Timor Movement: Human Rights, Mass Media and the Internet; Instrumentalization of the Networked Symbolic Mediation Conclusion: Browsing, News, Filters and Citizenship.Browsing, News, Filters and Citizenship Bibliograph

    Research and Technology Objectives and Plans Summary (RTOPS)

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    This publication represents the NASA research and technology program for FY-93. It is a compilation of the Summary portions of each of the RTOP's (Research and Technology Objectives and Plans) used for management review and control of research currently in progress throughout NASA. The RTOP Summary is designed to facilitate communication and coordination among concerned technical personnel in government, in industry, and in universities. The first section containing citations and abstracts of the RTOP's is followed by four indexes: Subject, Technical Monitor, Responsible NASA Organization, and RTOP Number

    Tempest: Geometries of Play

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    Atari’s 1981 arcade hit Tempest was a “tube shooter” built around glowing, vector-based geometric shapes. Among its many important contributions to both game and cultural history, Tempest was one of the first commercial titles to allow players to choose the game’s initial play difficulty (a system Atari dubbed “SkillStep”), a feature that has since became standard for games of all types. Tempest was also one of the most aesthetically impactful games of the twentieth century, lending its crisp, vector aesthetic to many subsequent movies, television shows, and video games. In this book, Ruggill and McAllister enumerate and analyze Tempest’s landmark qualities, exploring the game’s aesthetics, development context, and connections to and impact on video game history and culture. By describing the game in technical, historical, and ludic detail, they unpack the game’s latent and manifest audio-visual iconography and the ideological meanings this iconography evokes

    Space station systems: A bibliography with indexes (supplement 9)

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    This bibliography lists 1,313 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1989 and June 30, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included
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