1,720,964 research outputs found
A Trust-based Routing Framework for the Internet of Things
No full textThe intelligent connectivity of smart sensor devices commonly referred to as the Internet of Things (IoT) — is swiftly progressing productivity and communication levels and providing many functionalities throughout many organizations globally. The benefits heralded by the IoT’s revolution is threatened, however, by the general lack of understanding of IoT’s specific security demands thus, limiting its swift adoption and potential growth.
Two distinguishing features of IoT that makes it unique are the interconnection of billions of smart devices, and the resource-constrained nature of smart “things”. However, most IoT devices and applications operate with either no security; limited or insufficient security to protect the data they transmit during operation due to their limiting properties like CPU, memory capacity, battery life and mobility. This issue is further compounded for IoT system designers, as a global security framework has not been well defined, and most IoT system designers lack the knowledge or expertise to design or define secure IoT systems since this is a new and emerging technology.
The routing of data in the IoT network is a specific security area of concern. With the massive scale of data exchange between these devices, and no adequate security to protect the communication of data, compromising data routes becomes easy for attackers. This thesis therefore, proposes a secure routing communication framework called SecTrust, which scales on IoT size and provides acceptable network performances while not depleting the resource availability of these smart “things”. The proposed SecTrust is a secure Trust-based framework for IoT that provides a platform for trust computation, trust evaluation and trust formation among nodes. This framework provides a secure communication among the connected nodes. The framework further provides a system for the identification and isolation of malicious nodes operating within the network. In this system, every node computes the trustworthiness of its direct neighbours based on the computed direct trust value and the recommended trust value. While neighbours with high trust values are chosen for secure routing, nodes with lower trust values are categorised either as malicious, compromised, or perhaps selfish nodes that seek to preserve their resources like battery power. SecTrust consists of five main processes: trust calculation process, trust monitoring process, detection and isolation of malicious nodes, trust rating process and trust backup/recuperation process.
The development of this system provides insight into the use of modelling and analytical tools in building effective designs for P2P networks, through the design and development of trust computation, trust creation and trust propagation mechanisms, which are embedded, tested and validated using an IoT platform. The utility of SecTrust as a promising framework for IoT systems is demonstrated via its practical applications comprising: detection and isolation of malicious actors, management and sustenance of trust and recommendation systems in IoT networks and secure routing in IoT using a trust-based mechanism. Through the framework proposed, this thesis demonstrates that the SecTrust system showed promising performance results over other trust-based systems while simulations and testbed experiments offer proof-of-concept of the practicality of the proposed framework solution regardless of the operations of unreliable nodes, malicious nodes, selfish nodes, and even trust related attacks in the network.
Furthermore, this study is supported by proposing, implementing, and evaluating the trust-based system for large-scale IoT networks, and it constitutes three main parts. In the first part, the design and evaluation of SecTrust is reported. The effectiveness and transaction validity metrics are measured under purely naïve (attacking nodes working independently) and purely collective (attacking nodes colluding together) scenarios while scaling the network size from small size to a large-sized network.
The second part covered the actualization of the SecTrust framework into an IoT routing protocol (SecTrust-RPL). The SecTrust framework was embedded into the RPL routing protocol and simulated using an IoT platform. The simulation was conducted to demonstrate the performance of the trust framework in mitigating known IoT attacks while providing acceptable levels of network performance. The performance of SecTrust-RPL protocol was compared with the RPL routing protocol.
The third part was a testbed experiment, which served as a proof-of-concept to validate the simulation results presented and to show the practicality and efficacy of the SecTrust framework in mitigating IoT attacks in a real-world environment with minimal impact on network performance
A Trust-based Routing Framework for the Internet of Things
No full textThe intelligent connectivity of smart sensor devices commonly referred to as the Internet of Things (IoT) — is swiftly progressing productivity and communication levels and providing many functionalities throughout many organizations globally. The benefits heralded by the IoT’s revolution is threatened, however, by the general lack of understanding of IoT’s specific security demands thus, limiting its swift adoption and potential growth.
Two distinguishing features of IoT that makes it unique are the interconnection of billions of smart devices, and the resource-constrained nature of smart “things”. However, most IoT devices and applications operate with either no security; limited or insufficient security to protect the data they transmit during operation due to their limiting properties like CPU, memory capacity, battery life and mobility. This issue is further compounded for IoT system designers, as a global security framework has not been well defined, and most IoT system designers lack the knowledge or expertise to design or define secure IoT systems since this is a new and emerging technology.
The routing of data in the IoT network is a specific security area of concern. With the massive scale of data exchange between these devices, and no adequate security to protect the communication of data, compromising data routes becomes easy for attackers. This thesis therefore, proposes a secure routing communication framework called SecTrust, which scales on IoT size and provides acceptable network performances while not depleting the resource availability of these smart “things”. The proposed SecTrust is a secure Trust-based framework for IoT that provides a platform for trust computation, trust evaluation and trust formation among nodes. This framework provides a secure communication among the connected nodes. The framework further provides a system for the identification and isolation of malicious nodes operating within the network. In this system, every node computes the trustworthiness of its direct neighbours based on the computed direct trust value and the recommended trust value. While neighbours with high trust values are chosen for secure routing, nodes with lower trust values are categorised either as malicious, compromised, or perhaps selfish nodes that seek to preserve their resources like battery power. SecTrust consists of five main processes: trust calculation process, trust monitoring process, detection and isolation of malicious nodes, trust rating process and trust backup/recuperation process.
The development of this system provides insight into the use of modelling and analytical tools in building effective designs for P2P networks, through the design and development of trust computation, trust creation and trust propagation mechanisms, which are embedded, tested and validated using an IoT platform. The utility of SecTrust as a promising framework for IoT systems is demonstrated via its practical applications comprising: detection and isolation of malicious actors, management and sustenance of trust and recommendation systems in IoT networks and secure routing in IoT using a trust-based mechanism. Through the framework proposed, this thesis demonstrates that the SecTrust system showed promising performance results over other trust-based systems while simulations and testbed experiments offer proof-of-concept of the practicality of the proposed framework solution regardless of the operations of unreliable nodes, malicious nodes, selfish nodes, and even trust related attacks in the network.
Furthermore, this study is supported by proposing, implementing, and evaluating the trust-based system for large-scale IoT networks, and it constitutes three main parts. In the first part, the design and evaluation of SecTrust is reported. The effectiveness and transaction validity metrics are measured under purely naïve (attacking nodes working independently) and purely collective (attacking nodes colluding together) scenarios while scaling the network size from small size to a large-sized network.
The second part covered the actualization of the SecTrust framework into an IoT routing protocol (SecTrust-RPL). The SecTrust framework was embedded into the RPL routing protocol and simulated using an IoT platform. The simulation was conducted to demonstrate the performance of the trust framework in mitigating known IoT attacks while providing acceptable levels of network performance. The performance of SecTrust-RPL protocol was compared with the RPL routing protocol.
The third part was a testbed experiment, which served as a proof-of-concept to validate the simulation results presented and to show the practicality and efficacy of the SecTrust framework in mitigating IoT attacks in a real-world environment with minimal impact on network performance
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
On the design of fast handovers in mobile WiMAX networks
Full text linkThis Thesis is an embodiment of some research work carried out towards achieving faster and more reliable handover techniques in a Mobile WiMAX (Worldwide Interoperability for Microwave Access) network. Handover, also called handoff, is the critical mechanism that allows an ongoing session in a cellular mobile network like WiMAX to be seamlessly maintained without any call drop as the Mobile Station (MS) moves out of the coverage area of one base station (BS) to that of another. Mobile WiMAX supports three different types of handover mechanisms, namely, the hard handover, the Fast Base Station Switching (FBSS) and the Micro-Diversity Handover (MDHO). Out of these, the hard handover is the default handover mechanism whereas the other two are the optional schemes. Also, FBSS and MDHO provide better performance in comparison to hard handover, when it comes to dealing with the high-speed multimedia applications. However, they require a complex architecture and are very expensive to implement. So, hard handover is the commonly used technique accepted by the mobile broadband wireless user community including Mobile WiMAX users.
The existing Mobile WiMAX hard handover mechanism suffers from multiple shortcomings when it comes to providing fast and reliable handovers. These shortcomings include lengthy handover decision process, lengthy and unreliable procedure of selecting the next BS, i.e., the target BS (TBS) for handover, occurrence of frequent and unwanted handovers, long connection disruption times (CDT), wastage of channel resources, etc. Out of these, reducing the handover latency and improving the handover reliability are the two issues that our present work has focused on. While the process of selecting the TBS for handover adds to the overall delay in completing the process of handover, choosing a wrong TBS for handover increases the chance of further unwanted handovers to occur or even a call drop to occur. The latter greatly hampers the reliability of a handover.
In order to contribute to the solution of the above two problems of slow handover and unreliable handover, this Thesis proposes and investigates three handover techniques, which have been called Handover Techniques 1, 2 and 3, respectively. Out of these three techniques, the first two are fully MS-controlled while the third one is a dominantly serving BS-controlled. In Handover Techniques 1 and 2, which share between them some amount of commonness of ideas, the MS not only itself determines the need for a handover but also self-tracks its own independent movement with respect to the location of the (static) neighboring BSs (NBS). N both these handover techniques, the MS performs distance estimation of the NBSs from the signal strength received from the NBSs. But they (the two handover techniques) employ different kinds of “lookahead” techniques to independently choose, as the TBS, that NBS to which the MS is most likely to come nearest in the future. Being MS-controlled, both Handover Technique 1 and Handover Technique 2 put minimal handover-related workload on their respective SBSs who thus remain free to offer services to many more MSs. This interesting capability of the two handover techniques can increase the scalability of the WiMAX network considerably.
In Handover Technique 3, which is a BS-controlled one with some assistance received from the MS, the SBS employs three different criteria or parameters to select the TBS. The first criterion, a novel one, is the orientation matching between the MS’s direction of motion and the geolocation of each NBS. The other two criteria are the current load of each NBS (the load provides an indication of a BS’s current QoS capabilities) and the signal strength received by the MS from each NBS. The BS assigns scores to each NBS against each of the three independent parameters and selects the TBS, which obtains the highest weighted average score among the NBSs.
All three handover techniques are validated using simulation methods. While Handover Techniques 1 and 2 are simulated using Qualnet network simulator, for Handover Technique 3, we had to design, with barest minimum capability, our own simulation environment, using Python. Results of simulation showed that for Handover Techniques 1 and 2, it is possible to achieve around 45% improvement (approx) in the overall handover time by using the two proposed handover techniques. The emphasis in the simulation of the Handover Technique 3 was on studying its reliability in producing correct handovers rather than how fast handovers are. Five different arbitrary pre-defined movement paths of the MS were studied. Results showed that with orientation matching or orientation matching together with signal strength, reliability was extremely good, provided the pre-defined paths were reasonably linear. But reliability fell considerably when relatively large loads were also considered along with orientation matching and signal strength. Finally, the comparison between the proposed handover techniques in this Thesis and few other similar techniques in Mobile WiMAX proposed by other researchers showed that our techniques are better in terms providing fast, reliable and intelligent handovers in Mobile WiMAX networks, with scalability being an added feature
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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