The emergence of connected vehicles paradigm has made secure communication a key concern amongst the connected vehicles. Communication between the vehicles and Road Side Units (RSUs) is critical to disseminate message among the vehicles. We focus on secure message transmission in connected vehicles using multi-hop social networks environment to deliver the message with varying trustworthiness. We proposed a Geographic Social Trust Routing (GSTR) approach; messages are propagated using multiple hops and by considering the various available users in the vehicular network. GSTR is proposed in an application perspective with an assumption that the users are socially connected. The users are selected based on trustworthiness as defined by social connectivity. The route to send a message is calculated based on the highest trust level of each node by using the node's social network connections along the path in the network. GSTR determines the shortest route using the trusted nodes along the route for message dissemination. GSTR is made delay tolerant by introducing message storage in the cloud if a trustworthy node is unavailable to deliver the message. We compared the proposed approach with Geographic and Traffic Load based Routing (GTLR), Greedy Perimeter Stateless Routing (GPSR), Trust-based GPSR (T-GPSR). The performance results obtained show that GSTR ensures efficient resource utilization, lower packet losses at high vehicle densities.

<p>Abstract</p><p>As online social network services are becoming one of the dominant media channels the importance of disseminating messages through them is of high importance for governments, organizations, companies etc. The online social network services are several and changes rapidly as they grow and evolve. Being networks, the services give the user the tools to send, as well as receive text and information. This proposes us with yet another obstacle in communication via online social network services since sender and receiver merges together.</p><p>Online social network services and the Blogosphere, which essentially also is a network, exist in the context of Web 2.0. The crucial feature of Web 2.0 is to a large degree the harnessing of collective intelligence i.e. the collection of individual knowledge and information. Many of the tools and sites within Web 2.0 are therefore of a network structure, hence further stressing the importance to communicate via networks in general.</p><p>Network Analysis is the discipline through which we can see and understand the larger patterns of networks. In this thesis I have looked into three key concepts of Network Analysis; Weak Links, Growth and Preferential Attachment. I have found that we can use the knowledge of Network Analysis to disseminate messages via online social network services since it provides us with the raw structures of how networks tend to grow, and how messages tend to disseminate.</p><p>Title: Web 2.0 and Network Society – PR and Communication: The Challenge of Online Social Networks</p><p>Number of pages: 34</p><p>Author: Max Tandefelt</p><p>Tutor: Else Nygren</p><p>Course: Media and Communication Studies C</p><p>Period: HT 07</p><p>University: Division of Media and Communication, Department of Information Science, Uppsala University.</p><p>Purpose/Aim: Facilitate message dissemination through online social network services, as they are becoming one of the dominant media channels</p><p>Material/Method: Network Analysis</p><p>Main results: I have presented crucial concepts of Network Analysis that can be used for message dissemination via online social network services</p><p>Keywords: Online Social Network Services, Network Analysis, Web 2.0, Message Dissemination</p>

Abstract Intuition is one of human¡¦s instincts. It plays a major part in our daily decision-making. However, people experience intuition to different extents. Some may have deeper experience than others. Some may depend much on intuition in making decisions, while others tend to depend more on reason. Although there is risk in intuitional decision-making, many chiefs of businesses believe that intuition can be reliable for decision-making and therefore have made good achievements. The study investigated the intuition-experiential ability and intuition-experiential engagement of the chiefs in Kaohsiung¡¦s metals model industries and the degree of trust for intuitional decision-making of practical management on their company. The study found that the chief¡¦s age and years of service are not related to their trust in intuitional decision-making; intuition-experiential ability is also not related to their trust in intuitional decision-making. However, the intuition-experiential engagement is related to their trust in intuitional decision-making. The academic contribution this study makes is arranging intuitional conceptions and developing intuitional decision-making model, so that people can understand intuition better and come to have faith in intuition. Moreover, it raises Taiwanese people¡¦s interest in the research of intuition. This study concludes that, in aspect of practice of enterprises, chiefs can trust more in and make use of their intuition.

Abstract As online social network services are becoming one of the dominant media channels the importance of disseminating messages through them is of high importance for governments, organizations, companies etc. The online social network services are several and changes rapidly as they grow and evolve. Being networks, the services give the user the tools to send, as well as receive text and information. This proposes us with yet another obstacle in communication via online social network services since sender and receiver merges together. Online social network services and the Blogosphere, which essentially also is a network, exist in the context of Web 2.0. The crucial feature of Web 2.0 is to a large degree the harnessing of collective intelligence i.e. the collection of individual knowledge and information. Many of the tools and sites within Web 2.0 are therefore of a network structure, hence further stressing the importance to communicate via networks in general. Network Analysis is the discipline through which we can see and understand the larger patterns of networks. In this thesis I have looked into three key concepts of Network Analysis; Weak Links, Growth and Preferential Attachment. I have found that we can use the knowledge of Network Analysis to disseminate messages via online social network services since it provides us with the raw structures of how networks tend to grow, and how messages tend to disseminate. Title: Web 2.0 and Network Society – PR and Communication: The Challenge of Online Social Networks Number of pages: 34 Author: Max Tandefelt Tutor: Else Nygren Course: Media and Communication Studies C Period: HT 07 University: Division of Media and Communication, Department of Information Science, Uppsala University. Purpose/Aim: Facilitate message dissemination through online social network services, as they are becoming one of the dominant media channels Material/Method: Network Analysis Main results: I have presented crucial concepts of Network Analysis that can be used for message dissemination via online social network services Keywords: Online Social Network Services, Network Analysis, Web 2.0, Message Dissemination

No description available.

In Intelligent Transportation Systems (ITS), disseminating warning messages in a timely and efficient way through wireless short-range communications can save many lives and reduce traffic congestion. A geographical broadcast protocol provides data delivery to specified geographical areas, using multi-hop communications if needed. Among the main challenges for such protocols are forwarder selection and the reduction of the number of hops required to reach and cover the destination area.  In this thesis we propose an efficient geographical broadcast protocol called Preferred and Contention Based Forwarding (PCBF) and evaluate it through simulations. PCBF uses a combination of contention-based forwarding and selecting preferred forwarders also found in other protocols like Emergency Message Dissemination for Vehicular Environments (EMDV). Since the preferred forwarder is allowed to immediately forward the packet (evading contention among other potential forwarders), this approach reduces end-to-end delays. Notable extensions of PCBF compared to EMDV are the use of direct negative acknowledgements in case of unnecessary rebroadcasts and the use of forwarders outside the target region.  Our simulation results show that the PCBF protocol outperforms selected other protocols in terms of end-to-end delay, re-broadcast overhead and reliability in both sparse and dense networks.

No description available.

No description available.

Social media has become an important means of everyday communication. It is a mechanism for “sharing” and “resharing” of information. While social network platforms provide the means to users for resharing/reblogging (aka retweeting), it remains unclear what motivates users to share. Predicting the spread of content is quite important for several purposes such as viral marketing, popular news detection, personalized message recommendation and on-line advertisement. Social content systems store all the information produced in the interactions between users. However, to turn this data into information that allows us to extract patterns, it is important to consider the different phenomena involved in these interactions. In this work, two phenomena that influence the evolution of networks are studied for Twitter: diffusion of information and communication among users. Previous studies have shown that history of interaction among users and properties of the message are good attributes to understand the retweet behavior of users. Factors like content of message and time are less investigated. We propose a prediction model for retweet actions of users. It formulates a function which ranks the users according to how receptive they are to a particular message. The function generates a confidence score for the edges joining the initiator of the message and the followers. Two different pieces of information propagate through different users in the network. We divide the task of calculating confidence score into two parts. The first part is independent of the test tweet. It models transmission rate of the tie between the initiator and the follower. We call this as ‘Pairwise Influence Estimation’. The second part incorporates the tweet properties and user activeness as per time in the ranking function. The proposed model exploits all the dimensions of information dif-fusion process-influence, content and temporal properties. We have captured local aspects of diffusion. It has been observed that users do not read all the messages on their site. This results in shortcomings in the above models. Considering this, we first study the temporal behavior of users’ activities, which directly reflects their availability pertaining to the upcoming post. Also, as it is a continuous task of predicting retweet behavior, we design a user-centric, and temporally localized incremental classification model by considering the fact that users do not read all their tweets. We have tested the effectiveness of this model by using real data from Twitter. We demonstrate that the new proposed model is more accurate in describing the information propagation in microblog compared to the existing methods. Our model works well when we consider different classes of users depending on their activity patterns. In addition, we also investigate the parameters of the model for different classes of users. We report some interesting distinguishing patterns in retweeting behavior of users.

La convergencia de las telecomunicaciones, la informática, la tecnología inalámbrica y los sistemas de transporte, va a facilitar que nuestras carreteras y autopistas nos sirvan tanto como plataforma de transporte, como de comunicaciones. Estos cambios van a revolucionar completamente cómo y cuándo vamos a acceder a determinados servicios, comunicarnos, viajar, entretenernos, y navegar, en un futuro muy cercano. Las redes vehiculares ad hoc (vehicular ad hoc networks VANETs) son redes de comunicación inalámbricas que no requieren de ningún tipo de infraestructura, y que permiten la comunicación y conducción cooperativa entre los vehículos en la carretera. Los vehículos actúan como nodos de comunicación y transmisores, formando redes dinámicas junto a otros vehículos cercanos en entornos urbanos y autopistas. Las características especiales de las redes vehiculares favorecen el desarrollo de servicios y aplicaciones atractivas y desafiantes. En esta tesis nos centramos en las aplicaciones relacionadas con la seguridad. Específicamente, desarrollamos y evaluamos un novedoso protocol que mejora la seguridad en las carreteras. Nuestra propuesta combina el uso de información de la localización de los vehículos y las características del mapa del escenario, para mejorar la diseminación de los mensajes de alerta. En las aplicaciones de seguridad para redes vehiculares, nuestra propuesta permite reducir el problema de las tormentas de difusión, mientras que se mantiene una alta efectividad en la diseminación de los mensajes hacia los vehículos cercanos. Debido a que desplegar y evaluar redes VANET supone un gran coste y una tarea dura, la metodología basada en la simulación se muestra como una metodología alternativa a la implementación real. A diferencia de otros trabajos previos, con el fin de evaluar nuestra propuesta en un entorno realista, en nuestras simulaciones tenemos muy en cuenta tanto la movilidad de los vehículos, como la transmisión de radio en entornos urbanos, especialmente cuando los edificios interfieren en la propagación de la señal de radio. Con este propósito, desarrollamos herramientas para la simulación de VANETs más precisas y realistas, mejorando tanto la modelización de la propagación de radio, como la movilidad de los vehículos, obteniendo una solución que permite integrar mapas reales en el entorno de simulación. Finalmente, evaluamos las prestaciones de nuestro protocolo propuesto haciendo uso de nuestra plataforma de simulación mejorada, evidenciando la importancia del uso de un entorno de simulación adecuado para conseguir resultados más realistas y poder obtener conclusiones más significativas. / Martínez Domínguez, FJ. (2010). Improving Vehicular ad hoc Network Protocols to Support Safety Applications in Realistic Scenarios [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/9195