The Effects of Cognitive Stimulation of Instagram on Anxiety, Fear of Missing Out, Memory, and Self-Esteem

With the increasing use of social media in the daily lives of undergraduate college students, it is important to investigate the effects of social media on psychological well-being and cognitive function. Lillard and Peterson (2011) found that overstimulating children’s televisions shows, such as SpongeBob, negatively impacted children’s impulsive behaviors and attention. The current research focused on emerging adults and considered the effect of overstimulation of social media, specifically Instagram, on anxiety level, self-esteem, fear of missing out (FoMo), and memory. Participants were randomly assigned into either the control (coloring on an Ipad) or experimental (Instagram stimulation) group and after a set of pre-test questions regarding self-esteem and anxiety, participants were exposed to cognitive stimulation for 10 minutes. Then participants completed a post-test questionnaire of self-esteem, anxiety, memory recall, and fear of missing out (FoMo). Researchers hypothesized that the Instagram stimulation group would have lower levels of self-esteem, higher anxiety, higher levels of FoMo, and lower memory recall than those in the coloring group. Effects of exposure to Instagram has not been thoroughly researched, therefore it is an important avenue to study as emerging adults have an increasing habit of looking at Instagram on a regular basis. An independent samples t-test and a mixed-model ANOVA found that those exposed to Instagram had heightened levels of FoMo. In addition, participants, regardless of condition, experienced a significant increase in self-esteem from pre- to post-test. Future research may consider examining the effects of stimulation of Instagram regarding short-term memory and self-esteem

Position and Orientation Estimation through Millimeter Wave MIMO in 5G Systems

Millimeter wave signals and large antenna arrays are considered enabling technologies for future 5G networks. While their benefits for achieving high-data rate communications are well-known, their potential advantages for accurate positioning are largely undiscovered. We derive the Cram\'{e}r-Rao bound (CRB) on position and rotation angle estimation uncertainty from millimeter wave signals from a single transmitter, in the presence of scatterers. We also present a novel two-stage algorithm for position and rotation angle estimation that attains the CRB for average to high signal-to-noise ratio. The algorithm is based on multiple measurement vectors matching pursuit for coarse estimation, followed by a refinement stage based on the space-alternating generalized expectation maximization algorithm. We find that accurate position and rotation angle estimation is possible using signals from a single transmitter, in either line-of- sight, non-line-of-sight, or obstructed-line-of-sight conditions.Comment: The manuscript has been revised, and increased from 27 to 31 pages. Also, Fig.2, Fig. 10 and Table I are adde

Imagen de destino en redes sociales virtuales

Since destination image is an important construct for tourism research, cities and regions try to understand and to develop a positive image in order to guarantee the number of visitors and the tourism revenue. The main objective of this article was to develop a model of evaluation of destination image through the use of pictures shared in virtual social networks. We propose that the image of a destination can be analyzed through the way tourists picture the destination in virtual social networks. Hence, we have developed a measurement to evaluate destination image based on pictures posted on Instagram, and we made a model to analyze destination image based on pictures shared in virtual social network. Our method was composed by an analysis of 1,500 pictures of three important destinations in Brazil (Foz do Iguaçú, Rio de Janeiro, and Salvador). Our results contribute to tourism research by indicating that it is possible to determine the main characteristics of a destination by the pictures in virtual social networks, and by providing a 5-dimension model to do so. This study contributes to tourism research in two venues. First, we propose a method for evaluating destination image based on pictures posted in social media rather than the usual questionnaires. This may help scholars by providing an alternative way of evaluating destination image without recall, social desirability and non-response bias. And secondly, this study also contributes to practitioners and public policy in tourism by showing which characteristics of a destination image are more prominent to the destination image, based on virtual social networks.Como a imagem de destino é um importante construto para a pesquisa em turismo, as cidades e regiões tentam desenvolver uma imagem positiva para garantir o número de visitantes e a receita. O objetivo deste artigo é desenvolver um modelo de avaliação de imagem de destino através do uso de imagens compartilhadas em redes sociais virtuais. Propomos que a imagem de um destino possa ser analisada pela maneira como os turistas imaginam o destino em redes sociais virtuais. Assim, desenvolvemos uma medida para avaliar a imagem de destino com base em fotos publicadas no Instagram. Nosso método foi composto por uma análise de 1500 fotos de três importantes destinos no Brasil (Foz do Iguaçu, Rio de Janeiro e Salvador). Nossos resultados contribuem para a pesquisa em turismo, indicando que é possível determinar as principais características de um destino pelas imagens em redes sociais virtuais e fornecendo um modelo de 5 dimensões para fazê-lo. Este estudo contribui para a pesquisa em turismo em dois locais: propomos um método para avaliar a imagem de destino com base em imagens postadas em mídias sociais, em vez dos questionários usuais. Isso pode ajudar os estudiosos, fornecendo uma maneira alternativa de avaliar a imagem de destino sem recordação, desejo social e viés de não-resposta. Este estudo também contribui para os profissionais e políticas públicas em turismo, mostrando quais características de uma imagem de destino são mais proeminentes para a imagem de destino com base em redes sociais virtuais.Dado que la imagen de destino es una construcción importante para la investigación turística, las ciudades y regiones intentan entender y desarrollar una imagen positiva para garantizar el número de visitantes y los ingresos del turismo. El objetivo principal de este artículo es desarrollar un modelo de evaluación de la imagen de destino mediante el uso de imágenes compartidas en redes sociales virtuales. Proponemos que la imagen de un destino se pueda analizar a través de la forma en que los turistas representan el destino en las redes sociales virtuales. Por lo tanto, desarrollamos una medida para evaluar la imagen de destino basada en imágenes publicadas en Instagram y desarrollamos un modelo para analizar la imagen de destino basada en imágenes compartidas en una red social virtual. Nuestro método fue compuesto por un análisis de 1500 imágenes de tres destinos importantes en Brasil (Foz do Iguaçú, Río de Janeiro y Salvador). Nuestros resultados contribuyen a la investigación turística en tanto indican que es posible determinar las características principales de un destino por las imágenes en las redes sociales virtuales, y proporcionan un modelo de cinco dimensiones para hacerlo. Este estudio contribuye a la investigación turística en dos espacios. Por un lado, proponemos un método para evaluar la imagen de destino basada en imágenes publicadas en las redes sociales en lugar de los cuestionarios habituales; esto puede ayudar a los académicos al proporcionar una forma alternativa de evaluar la imagen de destino sin recordar la conveniencia social y el sesgo de no respuesta. Y por otro lado, este estudio también resulta provechoso para los profesionales y las políticas públicas en turismo al mostrar qué características de una imagen de destino son más prominentes a la imagen de destino basada en redes sociales virtuales.https://revistas.udem.edu.co/index.php/anagramas/article/view/252

Verifica dell'efficienza informativa del mercato. Metodologia dell'Event Study.

I mercati finanziari sono contraddistinti da una grande volatilità dei titoli quotati e scambiati. Questa volatilità la maggior parte delle volte deriva dell’andamento generale del mercato stesso, in altri casi, invece, scaturisce da fattori particolari che agiscono unicamente sul prezzo del singolo titolo. Lo scopo di tale lavoro è quello di comprendere se il mercato finanziario in esame, è un mercato efficiente in senso informativo, cioè se incorpora nel prezzo dei singoli titoli tutte le informazioni definite rilevanti che concernono questi ultimi. Nel corso dell’elaborato, verrà analizzato quale trend ci si attende da un titolo o quale evoluzione ha già avuto il titolo stesso in risposta ad un evento o ad una notizia price sensitive. Questi appena delineati, sono i fini che ci si prefigge di raggiungere nel momento in cui si decide di intraprendere un event study in finanza. Si tratta quindi di cercare una metodologia che consenta di comprendere queste reazioni dei prezzi; questo metodo è proprio l’Event Studies (ES). L’analisi quantitativa richiederà un’analisi storico-istituzionale del ciclo finanziario internazionale e una attenzione per le Unexpected News (UN), per misurarne l’impatto in una event window. Diversi sono i modelli di riferimento, e diverse sono le tecniche econometriche presenti nella letteratura sulla materia e utilizzate per l’analisi inferenziale. Saranno presentati modelli statici come il market model, ritenuto da molti studiosi, il modello che assicura le migliori performance e metodologie statistico-econometriche come il modello classico di regressione lineare (OLS) che assicura dei buoni risultati. Dopo la stima dei rendimenti mediante tale approccio, sarà svolta un’analisi di quelli direttamente imputabili all’evento considerato e che non rientrano nel normale andamento del titolo (Abnormal Returns). Su questi rendimenti anomali verranno poi condotti test statistici per la verifica della loro significatività

Performance Analysis of Hybrid 5G-GNSS Localization

\ua9 2018 IEEE. We consider a novel positioning solution combining millimeter wave (mmW) 5G and Global Navigation Satellite System (GNSS) technologies. The study is carried out theoretically by deriving the Fisher Information Matrix (FIM) of a combined 5G-GNSS positioning system and, subsequently, the position, rotation and clock-bias error lower bounds. We pursue a two-step approach, namely, computing first the FIM for the channel parameters, and then transforming it into the FIM of the position, rotation and clock-bias. The analysis shows advantages of the hybrid positioning in terms of i) localization accuracy, ii) coverage, iii) precise rotation estimation and iv) clock-error estimation. In other words, we demonstrate that a tight coupling of the two technologies can provide mutual benefits

Novel Solution for Multi-connectivity 5G-mmW Positioning

\ua9 2018 IEEE. The forthcoming fifth generation (5G) systems with high beamforming gain antenna units, millimeter-wave (mmWave) frequency bands together with massive Multiple Input Multiple Output (MIMO) techniques are key components for accurate positioning methods. In this paper, we propose the positioning technique that is relying on the sparsity in the MIMO-OFDM channel in time and spatial domains, together with effective beamforming methods. We will study the proposed solution in a multi-connectivity context, which has been considered so far for the purpose of improving the user equipment (UE) communication data rate. We utilize the multi-connectivity for positioning, in order to improve robustness to measurement errors and increase positioning service continuity. In particular, we show that when a UE that has connectivity to more base stations, the total power and delay needed for positioning can be reduced

5G mmwave positioning for vehicular networks

5G technologies present a new paradigm to provide connectivity to vehicles, in support of high data-rate services, complementing existing inter-vehicle communication standards based on IEEE 802.11p. As we argue, the specific signal characteristics of 5G communication turn out to be highly conducive for vehicle positioning. Hence, 5G can work in synergy with existing on-vehicle positioning and mapping systems to provide redundancy for certain applications, in particular automated driving. This article provides an overview of the evolution of cellular positioning and discusses the key properties of 5G as they relate to vehicular positioning. Open research challenges are presented