Search results for "Scheme"

No Reservations Required: Achieving Fairness between Wi-Fi and NR-U with Self-Deferral Only

2021

Wireless technologies coexisting in unlicensed bands should receive a fair share of the available channel resources, even when they use different access methods. We consider the problem of coexistence between Wi-Fi and New Radio Unlicensed (NR-U) nodes, which employ, respectively, a random and scheduled access scheme. The latter typically resorts to reservation signals (RSs), which allow keeping the control of the channel until the start of the next synchronized slot. This mechanism, although effective for increasing the channel access opportunities of scheduled-based nodes, is also a waste of channel resources. We investigate alternative solutions, based on self-deferral only. We built ana…

A Cognitive-based scheme for user reliability and expertise assessment in Q&A social networks

2011

Q&A social media has gained a great deal of attention during recent years. People rely on these sites to obtain information due to the number of advantages they offer as compared to conventional sources of knowledge (e.g., asynchronous and convenient access). However, for the same question one may find highly contradictory answers, causing ambiguity with respect to the correct information. This can be attributed to the presence of unreliable and/or non-expert users. In this work, we propose a novel approach for estimating the reliability and expertise of a user based on human cognitive traits. Every user can individually estimate these values based on local pairwise interactions. We examine…

An Efficient Multi-Show Unlinkable Attribute Based Credential Scheme for a Collaborative E-Health Environment

2017

Modern electronic healthcare (e-health) systems constitute collaborative environments in which patients' private health data are shared across multiple domains. In such environments, patients' privacy can be violated through the linkability of different user access sessions over patient health data. Therefore, enforcing anonymous as well as multi-session unlinkable access for the users in e-health systems is of paramount importance. As a way of achieving this requirement, more emphasis has been given to anonymous attribute credentials, which allows a user to anonymously prove the ownership of a set of attributes to a verifier and thereby gain access to protected resources. Among the existin…

Approximation-based adaptive tracking control of stochastic nonlinear systems with a general form

2014

In this paper, an approximation-based adaptive tracking control scheme is proposed for a class of stochastic nonlinear systems with a more general structure. Fuzzy logical systems are used to approximate unknown nonlinearities in the controller design procedure and the backstepping technique is utilized to construct a state-feedback adaptive controller. The proposed controller can guarantee that all the signals in the closed-loop system are fourth-moment semi-globally uniformly ultimately bounded and the tracking error eventually converges to a small neighborhood around the origin. Simulation results are used to show the effectiveness of the proposed control scheme.

Sharing Drawings with Smartphones in the Classroom – Art-Based Education in Social Sciences

2020

This article identifies the factors that indicate the opportunity of reviewing the methods in teaching economics in order to overcome the traditional teaching-learning scheme that overvalues rote learning and find formulas that facilitate the development of analytical skills. On the other hand, this work points out the importance of developing creative competences. One way to do this is to introduce artistic practices in the classroom, even in non-artistic subjects. In this work an experience of education based on the arts is presented. Thanks to smartphone cameras, students can share and project drawings in the classroom immediately to facilitate group learning. The proposal is to represen…

Elliptic Curve-Based Secure Multidimensional Aggregation for Smart Grid Communications

2017

In smart grid, data aggregation is considered as an essential paradigm in assessing information about current energy usage. To achieve the privacy-preserving goal, several homomorphic-based solutions have been proposed. However, these solutions either consider one-dimensional information or use costly pairing computation in order to ensure source authentication. In fact, smart grid data are likely to be multidimensional (e.g., time, purpose, and so on) for more accurate control. In addition, the aggregation node in smart grid needs to verify data that come from several smart meters in a residential area; hence, the verification must be cost-efficient. In this paper, we propose a scheme that…

Multi-cloud privacy preserving schemes for linear data mining

2015

This paper presents an approach to privacy-preserving data mining that relies upon a relatively simple secret sharing scheme. Its main feature is that users, sensitive data owners, are engaged in the secret sharing operations that protect their privacy. They are grouped in independent clouds connected to a central unit, the data miner, that only manages the aggregated data of each cloud, therefore avoiding the disclosure of information belonging to single nodes. We propose two privacy preserving schemes, with different privacy levels and communication costs. When designing them, we assume that some users' data might become inaccessible during the operation of the privacy preserving protocol…

A Study on scale factor in distributed differential evolution.

2011

This paper proposes the employment of multiple scale factor values within distributed differential evolution structures. Four different scale factor schemes are proposed, tested, compared and analyzed. Two schemes simply employ multiple scale factor values and two also include an update logic during the evolution. The four schemes have been integrated for comparison within three recently proposed distributed differential evolution structures and tested on several various test problems. Numerical results show that, on average, the employment of multiple scale factors is beneficial since in most cases it leads to significant improvements in performance with respect to standard distributed alg…

Securing Pathways into Teaching to Attract More Applicants ? An Analysis of the ‘Pre-professionalisation’ Scheme for Undergraduate Students in France…

2022

The expansion $\star$ mod $\bar{o}(\hbar^4)$ and computer-assisted proof schemes in the Kontsevich deformation quantization

2019

The Kontsevich deformation quantization combines Poisson dynamics, noncommutative geometry, number theory, and calculus of oriented graphs. To manage the algebra and differential calculus of series of weighted graphs, we present software modules: these allow generating the Kontsevich graphs, expanding the noncommutative & x22c6;-product by using a priori undetermined coefficients, and deriving linear relations between the weights of graphs. Throughout this text we illustrate the assembly of the Kontsevich & x22c6;-product up to order 4 in the deformation parameter Already at this stage, the & x22c6;-product involves hundreds of graphs; expressing all their coefficients via 149 w…