1,720,959 research outputs found
Key Recoverability in Wireless Sensor Networks
Get PDFIn case of an adversary that compromises a node in a wireless sensor network (WSN) and obtains its secret material, techniques for the detection of malicious or compromised nodes have been proposed in several papers. However, the ability to recover secure communications after a compromised node has been detected has not been thoroughly investigated. Such an ability allows to evaluate the level of proper functionality, i.e., the ratio of secure links in the network, that can be recovered after a successful attach and the withdrawal of the compromised secret material. This paper defines and discusses for the first time the recoverability property and provides the formulas to compute it for the main state-of-the-art key management schemes. All the formulas are validated through extensive simulation
A Smart Measuring System for Vehicle Dynamics Testing
Get PDFA fast measurement of the car handling performance is highly desirable to easily compare and assess different car setup, e.g. tires size and supplier, suspension settings, etc. Instead of the expensive professional equipment normally used by car manufacturers for vehicle testing, the authors propose a low-cost solution that is nevertheless accurate enough for comparative evaluations. The paper presents a novel measuring system for vehicle dynamics analysis, which is based uniquely on the sensors embedded in a smartphone and therefore completely independent on the signals available through vehicle CAN bus. Data from tri-axial accelerometer, gyroscope, GPS and camera are jointly used to compute the typical quantities analyzed in vehicle dynamics applications. In addition to signals such as yaw rate, lateral and longitudinal acceleration, vehicle speed and trajectory, normally available when working with Inertial Measurement Units (IMU) equipped with GPS, in the presented application the steering wheel angle is also measured, without additional sensors. The latter signal, besides being important for identifying the maneuver imposed by the driver, enables the usage of Kalman filters based on dynamic vehicle models (e.g. the single-track model) for the estimation of body sideslip angle. The system was tested during experimental campaigns on test tracks and the comparison between data from a professional measuring equipment and the Smart Measuring System showed a very good match. In the paper, hardware installation of smartphone and related accessories is discussed together with the main tasks of the algorithm implemented in the application, i.e. identification of smartphone orientation, steering wheel angle measurement, Kalman filter sideslip angle estimators (based on kinematic and single-track models). Furthermore, the time histories of the vehicle dynamics quantities during a lap on a handling test track are shown and compared with reference signals from the professional equipment. The proposed system proved to be a promising cost-A nd time-effective solution for vehicle dynamics testing
Adaptive error resilient mechanisms for real-time multimedia streaming over inter-vehicle communication networks
No full textTo allow real-time streaming of loss tolerant flows such as multimedia streams in inter-vehicle communication network, we propose a cross-layer technique based on proactive error correction and interleaving algorithms. The proposed technique optimizes the FEC/interleaving channel coding parameters based on network layer information under real-time constraints. It is implemented at packet level to allow a straightforward adaption in the existing wireless devices. By resorting to standard compliant, real-time RTCP reports, we also develop and optimize an adaptive technique that is able to match fast channel variations and reduce both the overhead required by the proactive error recovery scheme and the additional delay introduced by the interleaver. Simulations based on Gilbert-Elliott wireless channel model show that the proposed adaptive technique without optimizations is able to gain over 0.9 dB in terms of video PSNR with respect to the standard transmission, while in its optimized version, the gain is over 1.5 dB PSNR, with a total overhead of about 12%. © Springer Science+Business Media, LLC 2012
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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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