Search results for "computer networks"
showing 10 items of 860 documents
Multi-domain feature extraction for small event-related potentials through nonnegative multi-way array decomposition from low dense array EEG
2013
Non-negative Canonical Polyadic decomposition (NCPD) and non-negative Tucker decomposition (NTD) were compared for extracting the multi-domain feature of visual mismatch negativity (vMMN), a small event-related potential (ERP), for the cognitive research. Since signal-to-noise ratio in vMMN is low, NTD outperformed NCPD. Moreover, we proposed an approach to select the multi-domain feature of an ERP among all extracted features and discussed determination of numbers of extracted components in NCPD and NTD regarding the ERP context.
Permanently online and permanently connected : development and validation of the Online Vigilance Scale
2017
Smartphones and other mobile devices have fundamentally changed patterns of Internet use in everyday life by making online access constantly available. The present paper offers a theoretical explication and empirical assessment of the concept of online vigilance, referring to users' permanent cognitive orientation towards online content and communication as well as their disposition to exploit these options constantly. Based on four studies, a validated and reliable self-report measure of online vigilance was developed. In combination, the results suggest that the Online Vigilance Scale (OVS) shows a stable factor structure in various contexts and user populations and provides future work i…
Uso problemático del smartphone: el papel de los Cinco Grandes, la Tríada Oscura y la impulsividad
2021
Abstract. Este estudio examinó las relaciones entre los rasgos de personalidad de los cinco grandes (extraversión, afabilidad, neuroticismo, responsabilidad y apertura a la experiencia), la tríada oscura (maquiavelismo, psicopatía y narcisismo), la impulsividad y el uso problemático del smartphone. Doscientos dos participantes (52.48% hombres), con edades comprendidas entre los 18 y los 58 años, completaron el Ten-Item Personality Inventory, la Smartphone Addiction Scale, el Dirty Dozen y la escala de impulsividad de Plutchik. Los análisis de correlación mostraron que el uso problemático del smartphone estaba significativamente asociado a la extraversión, el neuroticismo, la impulsividad y …
Unemployment, Personality Traits, and the Use of Facebook
2021
Different personality traits respond differently to unfavourable life situations. Unemployment can have several negative social, economic, and domestic consequences. Many people use social media for a variety of reasons. The aim of this study is to examine the way different personality traits respond to Facebook in the period of unemployment. Data was obtained from 3,002 unemployed respondents in Nigeria. The study used regression model to analyse the data. Among the five personality traits, results indicated that the relationship between neuroticism and online social support was negative. However, the relationship between online social support and satisfaction was positive. The study highl…
Finite-Size and Illumination Conditions Effects in All-Dielectric Metasurfaces
2022
Dielectric metasurfaces have emerged as a promising alternative to their plasmonic counterparts due to lower ohmic losses, which hinder sensing applications and nonlinear frequency conversion, and their larger flexibility to shape the emission pattern in the visible regime. To date, the computational cost of full-wave numerical simulations has forced the exploitation of the Floquet theorem, which implies infinitely periodic structures, in designing such devices. In this work, we show the potential pitfalls of this approach when considering finite-size metasurfaces and beam-like illumination conditions, in contrast to the typical infinite plane-wave illumination compatible with the Floquet t…
An AmI-Based Software Architecture Enabling Evolutionary Computation in Blended Commerce: The Shopping Plan Application
2015
This work describes an approach to synergistically exploit ambient intelligence technologies, mobile devices, and evolutionary computation in order to support blended commerce or ubiquitous commerce scenarios. The work proposes a software architecture consisting of three main components: linked data for e-commerce, cloud-based services, and mobile apps. The three components implement a scenario where a shopping mall is presented as an intelligent environment in which customers use NFC capabilities of their smartphones in order to handle e-coupons produced, suggested, and consumed by the abovesaid environment. The main function of the intelligent environment is to help customers define shopp…
Mitigating DDoS using weight‐based geographical clustering
2020
Distributed denial of service (DDoS) attacks have for the last two decades been among the greatest threats facing the internet infrastructure. Mitigating DDoS attacks is a particularly challenging task as an attacker tries to conceal a huge amount of traffic inside a legitimate traffic flow. This article proposes to use data mining approaches to find unique hidden data structures which are able to characterize the normal traffic flow. This will serve as a mean for filtering illegitimate traffic under DDoS attacks. In this endeavor, we devise three algorithms built on previously uncharted areas within mitigation techniques where clustering techniques are used to create geographical clusters …
Estado de la investigación sobre la colaboración en Entornos Virtuales de Aprendizaje
2019
El aprendizaje colaborativo posee una tradición teórica y práctica amplia en la educación general, como en la educación superior. No obstante, la actividad de coordinación entre personas que buscan aprender no es sencilla de gestionar. Esta complejidad aumenta cuando entre la actividad colaborativa surge un nuevo componente, la tecnología. ¿Qué se ha avanzado sobre el aprendizaje colaborativo mediado tecnológicamente? Este trabajo tiene como objetivo analizar el estado de la investigación sobre aprendizaje colaborativo en Educación Superior en los Entornos Virtuales de Aprendizaje (EVA). Para ello se realiza un análisis bibliométrico de las publicaciones indexadas de la base de datos SCOPUS…
Arc routing problems: A review of the past, present, and future
2020
[EN] Arc routing problems (ARPs) are defined and introduced. Following a brief history of developments in this area of research, different types of ARPs are described that are currently relevant for study. In addition, particular features of ARPs that are important from a theoretical or practical point of view are discussed. A section on applications describes some of the changes that have occurred from early applications of ARP models to the present day and points the way to emerging topics for study. A final section provides information on libraries and instance repositories for ARPs. The review concludes with some perspectives on future research developments and opportunities for emergin…
Modelling and Analysis of Nonstationary Vehicle-to-Infrastructure Channels with Time-Variant Angles of Arrival
2018
In mobile radio channel modelling, it is generally assumed that the angles of arrival (AOAs) are independent of time. This assumption does not in general agree with real-world channels in which the AOAs vary with the position of a moving receiver. In this paper, we first present a mathematical model for the time-variant AOAs. This model serves as the basis for the development of two nonstationary multipath fading channels models for vehicle-to-infrastructure communications. The statistical properties of both channel models are analysed with emphasis on the time-dependent autocorrelation function (ACF), time-dependent mean Doppler shift, time-dependent Doppler spread, and the Wigner-Ville sp…