1,721,084 research outputs found
Cost and Collision Minimizing Forwarding Schemes for Wireless Sensor Networks
Full text linkThe paper presents a novel integrated MAC/routing scheme for wireless sensor networking. Our design objective is to elect the next hop for data forwarding by minimizing the number of messages and, at the same time, maximizing the probability of electing the best candidate node. To this aim, we represent the suitability of a node to act as the relay by means of locally calculated and generic cost metrics. Based on these costs, we analytically model the access selection problem through dynamic programming techniques thereby devising the optimal access policy. We subsequently derive a contention-based MAC and forwarding scheme, named cost and collision minimizing routing (CCMR). Both analytical and simulation results are given to demonstrate the effectiveness of our technique by comparing its performance against state of the art solutions
Cost- and Collision-Minimizing Forwarding Schemes for Wireless Sensor Networks: Design, Analysis, and Experimental Validation
No full textThe paper presents an original integrated MAC and routing scheme for wireless sensor networks. Our design objective is to elect the next hop for data forwarding by jointly minimizing the amount of signaling to complete a contention and maximizing the probability of electing the best candidate node. Toward this aim, we represent the suitability of a node to be the relay by means of locally calculated and generic cost metrics. Based on these costs, we analytically model the access selection problem through dynamic programming techniques, which we use to find the optimal access policy. Hence, we propose a contention-based MAC and forwarding technique, called Cost- and Collision-Minimizing Routing (CCMR). This scheme is then thoroughly validated and characterized through analysis, simulation, and experimental results
Smartphone Identification via Passive Traffic Fingerprinting: A Sequence-to-Sequence Learning Approach
No full textPassive cyber-security attacks do not require any modification of the data stream generated by the victim, nor the creation of a false statement; in particular, those attacks based on statistical analysis aim at acquiring sensible information by just analyzing traffic patterns. Our work sits on the conjecture that the PDCCH, which is transmitted in clear text, may be effectively used to statistically characterize the traffic generated by a smartphone in standby mode. Through this statistical signature, the attacker may then infer whether an unknown traffic pattern is generated by the victim user's terminal, guessing if the victim is in a certain geographical area, and in turn gaining the ability to track the victim's movements and/or to profile their habits. In this work, we propose a data collection and processing framework that successfully obtains such signatures. User data patterns (transport block sizes and communications direction) are retrieved by analyzing the mobile network scheduling. Hence, a sequence-to-sequence learning framework to extract smartphone signatures from passive traffic is put forward, and is experimentally validated using a dataset of 40 user traces, successfully identifying up to 90 percent of the users
Supplemental Material - Effect of aspect ratio, bulk density, and production date of multi-walled carbon nanotubes on the electrical conductivity of polypropylene and polycarbonate/multi-walled carbon nanotube nanocomposites
No full textSupplemental Material for Effect of aspect ratio, bulk density, and production date of multi-walled carbon nanotubes on the electrical conductivity of polypropylene and polycarbonate/multi-walled carbon nanotube nanocomposites by Bui N Duc and Younggon Son in Journal of Composite Materials</p
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
An Integrated System for Secure Code Distribution in Wireless Sensor Networks
No full textThis paper presents a Secure Code Update (SCU) system for Wireless Sensor Networks (WSNs). This solution achieves different security goals. First, through a dedicated authentication protocol it provides protection against the corruption of code images during their dissemination. Authentication routines exploit a lightweight asymmetric T-time signature algorithm [1] and allow the out-of-order reception of data blocks. Second, confidentiality is provided through the implementation of an optimized symmetric encryption suite, designed to leverage the processing capabilities offered by typical IEEE 802.15.4 radios. Last, our solution offers protection against denial of service attacks. In the first part of the paper we present the integration of this security system with the SYNAPSE++ reprogramming protocol [2], focusing on the description of the security suite as weD as on its salient implementation aspects. After this, we present experimental results that demonstrate the effectiveness against security attacks and quantify the loss in performance due to the addition of security components to SYNAPSE++
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