SECURE AND EFFICIENT INFORMATION MANAGEMENT IN DELAY(DISRUPTION) TOLERANT NETWORK

In environments like international military coalitions on the battlefield or multi-party relief work in a disaster zone, multiple teams are deployed to serve different mission goals by the command-and-control center (CC). They may need to survey damages and send information to the CC for situational awareness and also transfer messages to each other for mission purposes. However, due to the damaged network infrastructure in the emergency, nodes need to relay messages using the store and forward paradigm, also called Delay-tolerant Networks (DTNs). In DTN, the limited bandwidth, energy, and contacts among the nodes, and their interdependency impose several challenges such as sensitive data leakage to malicious nodes, redundant data generation, limited and delayed important message delivery, non-interested messages in storage, etc. We aim to focus on solving these challenges. We propose message fragmentation for secure message transfer because existing public-private-key cryptographic approaches may not work due to the unavailability of Public Key Infrastructure (PKI). Besides, to ensure more message delivery, redundant fragments are generated. However, too much redundancy may consume the energy and bandwidth of the nodes while transferring similar messages. Hence, we propose to send diverse content and limit the redundancy. Again, the dynamic environment we consider is prone to many adverse and sudden events. We aim to respond to these events by sending the event-related message to the CC fast with the help of intermediate nodes. The nodes are interested in certain types of content defined by their mission and interest. Therefore, we target to learn nodes\u27 interests using Reinforcement Learning so that the nodes can populate themselves with the messages according to their mission requirements and increase the collaboration among them. Our future work will include machine learning techniques for predicting important places where node encounters the most and to cache data for each other according to their interest, encounter frequency, and encounter locations --Abstract, p. i

Task Allocation among Connected Devices: Requirements, Approaches and Challenges

Task allocation (TA) is essential when deploying application tasks to systems of connected devices with dissimilar and time-varying characteristics. The challenge of an efficient TA is to assign the tasks to the best devices, according to the context and task requirements. The main purpose of this paper is to study the different connotations of the concept of TA efficiency, and the key factors that most impact on it, so that relevant design guidelines can be defined. The paper first analyzes the domains of connected devices where TA has an important role, which brings to this classification: Internet of Things (IoT), Sensor and Actuator Networks (SAN), Multi-Robot Systems (MRS), Mobile Crowdsensing (MCS), and Unmanned Aerial Vehicles (UAV). The paper then demonstrates that the impact of the key factors on the domains actually affects the design choices of the state-of-the-art TA solutions. It results that resource management has most significantly driven the design of TA algorithms in all domains, especially IoT and SAN. The fulfillment of coverage requirements is important for the definition of TA solutions in MCS and UAV. Quality of Information requirements are mostly included in MCS TA strategies, similar to the design of appropriate incentives. The paper also discusses the issues that need to be addressed by future research activities, i.e.: allowing interoperability of platforms in the implementation of TA functionalities; introducing appropriate trust evaluation algorithms; extending the list of tasks performed by objects; designing TA strategies where network service providers have a role in TA functionalities’ provisioning

Incentive Mechanisms for Participatory Sensing: Survey and Research Challenges

Participatory sensing is a powerful paradigm which takes advantage of smartphones to collect and analyze data beyond the scale of what was previously possible. Given that participatory sensing systems rely completely on the users' willingness to submit up-to-date and accurate information, it is paramount to effectively incentivize users' active and reliable participation. In this paper, we survey existing literature on incentive mechanisms for participatory sensing systems. In particular, we present a taxonomy of existing incentive mechanisms for participatory sensing systems, which are subsequently discussed in depth by comparing and contrasting different approaches. Finally, we discuss an agenda of open research challenges in incentivizing users in participatory sensing.Comment: Updated version, 4/25/201

Location reliability and gamification mechanisms for mobile crowd sensing

People-centric sensing with smart phones can be used for large scale sensing of the physical world by leveraging the sensors on the phones. This new type of sensing can be a scalable and cost-effective alternative to deploying static wireless sensor networks for dense sensing coverage across large areas. However, mobile people-centric sensing has two main issues: 1) Data reliability in sensed data and 2) Incentives for participants. To study these issues, this dissertation designs and develops McSense, a mobile crowd sensing system which provides monetary and social incentives to users. This dissertation proposes and evaluates two protocols for location reliability as a step toward achieving data reliability in sensed data, namely, ILR (Improving Location Reliability) and LINK (Location authentication through Immediate Neighbors Knowledge). ILR is a scheme which improves the location reliability of mobile crowd sensed data with minimal human efforts based on location validation using photo tasks and expanding the trust to nearby data points using periodic Bluetooth scanning. LINK is a location authentication protocol working independent of wireless carriers, in which nearby users help authenticate each other’s location claims using Bluetooth communication. The results of experiments done on Android phones show that the proposed protocols are capable of detecting a significant percentage of the malicious users claiming false location. Furthermore, simulations with the LINK protocol demonstrate that LINK can effectively thwart a number of colluding user attacks. This dissertation also proposes a mobile sensing game which helps collect crowd sensing data by incentivizing smart phone users to play sensing games on their phones. We design and implement a first person shooter sensing game, “Alien vs. Mobile User”, which employs techniques to attract users to unpopular regions. The user study results show that mobile gaming can be a successful alternative to micro-payments for fast and efficient area coverage in crowd sensing. It is observed that the proposed game design succeeds in achieving good player engagement

Improving the transfer of coastal scientific knowledge : from concept to implementation

Tese de doutoramento, Geologia (Geodinâmica), Universidade de Lisboa, Faculdade de Ciências, 2016Achieving coastal sustainability requires a comprehensive knowledge of the coastal environment. In this context, scientific knowledge plays a major role in understanding coastal processes at a wide range of spatial and temporal scales, as well as in the integration of different types of knowledge. However, scientific knowledge as not been used in full for the development of science-based coastal policies and management strategies, and ineffective scientific knowledge transfer arises as a major obstacle in knowledge integration. Several reasons for ineffective knowledge transfer have been suggested in the literature, most of which related with communication gaps. The main objective of the present work is to find means to improve the transfer of coastal scientific knowledge fostering its incorporation into coastal management. This study was based upon a conceptual approach supported in a comprehensive literature review and grounded in theoretical developments. Results benefits from the author’s experience gathered from different projects developed under the framework of the resent study. The first step to achieve the main objective of this work was to identify who are the key coastal actors and understanding the way they interact: this is of paramount importance in a knowledge-transferring framework as they are the audience that scientists aim to reach. Beside scientists, two other key coastal actors are policy-makers and managers, and society. Policy-makers and managers are responsible for the regulation of the coastal zone uses by establishing and implementing the policy framework for the coast. Society arises also as a key coastal actor as people benefit from the services provided by the coastal environment. Although society is frequently regarded as a passive intervenient, the fact is that the role of society in the definition of coastal strategies is increasing. Key coastal actors, their roles and links are schematized in The Coastal Knowledge Triangle. The second step was to identify the challenges faced by scientists in fostering scientific knowledge. Two major challenges were identified: the need to foster engagement among coastal actors, and the need to properly frame the message to be delivered. Engagement is grounded on empathy and goes beyond simple awareness of the problem. Four key enablers for successfully building engagement were identified: willingness, trust, competence and commitment. Framing the message helps turning scientific data into meaningful information for the target audience, and implies choosing the more adequate language (i.e., the manner in which scientific knowledge is traduced) and channels of communication (i.e., the manner in which the message is sent) according to the audience’s specificities. Interpersonal communication, video and websites are examples of widely used channels in science communication. The most adequate languages to traduce scientific knowledge are discourse (i.e., conceptual generalization of conversation), images (including photographs and graphical representations) and indicators. This study suggests that indicators the most efficient way to transmit inherently complex information in a simplified and applicable form, a conclusion in line with several international organizations. Considering their relevance, a common framework for the establishment of coastal geoindicators for sandy coast environments was developed in the scope of the present work. The third step was to identify mechanisms that scientists can adopt to connect with their audience. Each mechanism accounts for the audience specificities and conveys the message in a different way leading to different types and quantity of feedback. If adequately used, mechanisms improve the transfer of scientific knowledge by fostering engagement, minimizing framing effort and optimizing audiences’ feedback. The most widely known (and adopted) mechanism to transfer scientific knowledge is outreach (as formal education is not encompassed in the scope of this work). However, scientists’ must be aware that other mechanisms are available: crowdsourcing, managers-oriented tools and co-production. These mechanisms although in earlier stages of development are promising alternatives and should be considered as major opportunities to foster knowledge transfer. In the scope of the present work, a conceptual model was developed to help scientists in selecting the most adequate mechanism to convey the coastal message. In this selection, scientists must weigh the level of engagement of the audience and account for the feedback raised by each mechanism: outreach leads to coastal awareness; crowdsourcing to data generation; management-oriented tools generate information, and co-production boosts knowledge. The application of each mechanism and related feedback is thoroughly discussed in this work grounded in real-world applications. The adequate use of these mechanisms will lead to a knowledge-based society and will increase the participation of key coastal actors in decision-making. Therefore, scientists should actively pursue the goal of transferring their knowledge outside of the scientific community, by adopting the proper mechanisms to connect with their audience, developing their framing skills and acknowledging the benefits of engaging with others. Not only this is a social responsibility of scientists but, ultimately, it will also benefit the value of research endeavors towards [coastal] sustainability.A sustentabilidade da zona costeira só é possível através da integração do conhecimento (lato sensu) na definição de estratégias de planeamento e gestão. Neste contexto, o conhecimento científico apresenta uma importância fundamental na compreensão dos processos que condicionam a evolução costeira, mas também na integração de outras fontes de conhecimento (não científico) associados à zona costeira. No entanto, presentemente, a integração do conhecimento científico na gestão da zona costeira é geralmente efetuada de forma não-sistemática e, na maioria dos casos, em contextos reativos. Esta situação deve-se essencialmente a constrangimentos associados à transferência do conhecimento científico entre as comunidades científicas e não científicas, relacionados com limitações na comunicação entre as partes. O principal objectivo deste trabalho é definir estratégias que potenciem a transferência do conhecimento científico, entre as comunidades científica e não científica, promovendo a sua integração no planeamento e gestão da zona costeira. Este trabalho é baseado numa abordagem conceptual suportada em vasta pesquisa bibliográfica e no desenvolvimento de um conjunto de projetos que foram desenvolvidos e implementados no âmbito deste estudo. A primeira fase deste trabalho consistiu na identificação dos principais atores da zona costeira. Para além dos cientistas, responsáveis pela geração do conhecimento científico, foram identificados os decisores políticos e gestores, e a sociedade em geral: os decisores políticos e gestores enquanto responsáveis pela regulação da zona costeira através do estabelecimento e implementação dos instrumentos legais de ordenamento da orla costeira; a sociedade uma vez que beneficia, direta e indiretamente, dos serviços fornecidos pela zona costeira e pelo ao seu papel cada vez mais interventivo e de maior relevância na tomada de decisão. De forma a conceptualizar as relações entre os principais atores da zona costeira foi desenvolvido o “Triângulo do Conhecimento Costeiro” (The Coastal Knowledge Triangle). A segunda fase constituiu na identificação dos desafios que os cientistas encontram na transferência do conhecimento científico. Neste contexto foram identificadas duas ações que podem atuar como catalisadores da transferência do conhecimento: promover o engajamento (engagement) entre os principais atores e enquadrar (framing) a “mensagem” num formato que considere as especificidades da audiência. O engajamento implica o envolvimento dos cientistas não só na identificação do problema mas também na sua resolução e beneficia da existência de (maior empatia entre as diferentes partes envolvidas. O enquadramento da mensagem implica a tradução e disponibilização do conhecimento científico em dados e informação relevante para os outros atores (receptores da mensagem) através da utilização de uma linguagem (forma como a informação é traduzida) e de canais de comunicação adequados. No âmbito do presente trabalho, foram identificadas com linguagens mais adequadas para a transferência do conhecimento científico, o discurso, as imagens (incluindo fotografias e gráficos) e os indicadores. Os indicadores foram considerados como a linguagem mais adequada para transmitir informação inerentemente complexa de uma forma simples e aplicável. Esta constatação está de acordo com as orientações de várias organizações internacionais de reconhecido mérito. Neste sentido, no âmbito do presente trabalho foi desenvolvido um quadro de referência para o estabelecimento e reporte de geoindicadores orientados para a descrição do estado e evolução de litorais arenosos. Por último foram identificados diferentes mecanismos para os cientistas se relacionarem com a audiência e que têm como objetivo potenciar a transferência do conhecimento. Cada um dos mecanismos pressupõe o estabelecimento de diferentes tipos de ligação com a audiência gerando, por sua vez, diferentes tipos de resposta. Adicionalmente, se devidamente utilizados, estes mecanismos não só promovem a transferência do conhecimento mas também promovem o engajamento, minimizam os esforços no enquadramento da mensagem e otimizam a resposta da audiência. O mais conhecido, e utilizado, mecanismo de transferência do conhecimento científico é a divulgação científica (outreach). No entanto, existem outras formas para transferir conhecimento científico: a aquisição coletiva de dados (crowdsourcing), ferramentas de apoio à gestão e co-produção. Estes mecanismos, apesar de se encontrarem numa fase mais inicial de desenvolvimento e aplicação, constituem alternativas de elevado potencial na transferência do conhecimento. Neste estudo, todos estes mecanismos são apresentados e discutidos com base em projetos concretos desenvolvidos no âmbito deste trabalho. Para orientar os cientistas na seleção do mecanismo mais adequado para transferirem a sua mensagem foi desenvolvido um modelo conceptual. Nesta seleção, os cientistas devem considerar o nível de engajamento entre os atores e o tipo de resposta que os cientistas desejam gerar na audiência: enquanto a divulgação científica promove a literacia e a sensibilização, a aquisição coletiva de dados promove a geração de dados, as ferramentas orientadas para o apoio à gestão promovem a geração de informação e a coprodução a geração de (novo) conhecimento. Verificou-se que a adoção dos diferentes os mecanismos tem um vasto potencial na promoção uma sociedade baseada no conhecimento e potencia a participação dos diferentes atores costeiros no processo de decisão. Neste sentido, os cientistas devem promover ativamente a transferência do conhecimento científico para além das fronteiras da comunidade científica. É ainda fundamental que os cientistas desenvolvam as suas competências no enquadramento da mensagem e reconheçam os benefícios de interagir com os outros atores. Esta atitude é uma responsabilidade social dos cientistas que, em última instância, irá valorizar os seus esforços na geração do conhecimento científico e contribuir para a sustentabilidade da zona costeira.Fundação para a ciência e a Tecnologia (FCT, SFRH/BD/82223/2011