Experimental study of MIMO-OFDM transmissions at 94 GHz in indoor environments

Millimeter wave (mm-wave) frequencies have been proposed to achieve high capacity in 5G communications. Although meaningful research on the channel characteristics has been performed in the 28, 38and 60 GHz bands ─in both indoor and short-range scenarios─,only a small number of trials (experiments) have been carried out in other mm-wave bands. The objective of this work is to study the viability and evaluate the performance of the 94 GHz frequency band for MIMO-OFDM transmission in an indoor environment. Starting from a measurement campaign, the performance of MIMO algorithms is studied in terms of throughput for four different antenna configurations.This work was supported in part by the Ministerio de Economía y Competitividad MINECO, Spain under Grant TEC2016-78028-C3-2-P, and in part by the European FEDER funds

Causes and success of brand deletions. The role of brand orientation

La eliminación de una marca es una decisión crítica dentro de la estrategia de marketing de una empresa. Pese a que en los últimos años muchas organizaciones han tomado este tipo de decisión y han acometido drásticos programas de eliminación de marcas, la literatura sobre este tema es muy escasa y fragmentada, y son múltiples las cuestiones que se deben abordar. Concretamente, en este trabajo nos proponemos examinar la influencia de las causas de eliminación de una marca –previamente clasificadas en proactivas y reactivas– en el éxito de la decisión. Además, exploramos el efecto que la orientación a la marca tiene en la mayor o menor ocurrencia de eliminaciones por causas proactivas o reactivas. Implícitamente, en el trabajo proponemos que la orientación a la marca tendrá un doble efecto indirecto positivo en el éxito de una eliminación. En primer lugar, a través de incremento de eliminaciones exitosas que ocurren por causas proactivas y, en segundo, por la reducción de eliminaciones no exitosas que sobrevienen por causas reactivas. La propuesta investigadora que realizamos se testa sobre una muestra de 155 casos de eliminación de marca. Los análisis preliminares indican que la orientación a la marca contribuye al éxito a través de la adopción de eliminaciones enfocadas en el aprovechamiento de oportunidades de la marca, tales como un mayor ajuste estratégico o unos menores costes de oportunidad. Además, la orientación a la marca previene de realizar eliminaciones simplemente por causas problemáticas, eliminaciones que no acaban arrojando grandes resultados.Brand deletion (BD) is a critical decision within a firm’s marketing strategy. Despite in recent years many organizations have pruned their brand portfolios and undertaken drastic BD programs, the literature on this topic is extremely scarce and fragmented, and several issues of BD can be investigated. This research is primarily concerned with the study of the impact of BD causes –previously classified as proactive versus reactive– on BD success. In addition, we explore the effect of the firm’s brand orientation on the occurrence of deletions by proactive versus reactive causes. Implicitly, we suggest that brand orientation will have a double positive indirect effect on BD success: first, through the increase of successful BDs due to proactive causes and, second, by the reduction of unsuccessful BDs precipitated by reactive causes. Our research proposal is tested on a sample of 155 cases of BD. Preliminary findings indicate that brand orientation contributes to the BD success through the adoption of BDs focused on taking advantage of brand opportunities, such as searching for a better strategic fit or avoiding opportunity costs. Besides, brand orientation prevents deletions due to merely problematic causes, deletions that, after all, do not generate success

Sequences of Discourse in e-Learning Environments

In this article we describe the research we have carried out aimed at contributing conceptual and methodological tools to help in understanding better how online teaching and learning works. We develop a qualitative analysis of asynchronous forum of several e-learning courses identifying sequences or moves of teaching discours

Didactic interaction in e-learning: New styles for new environments

This article presents the results of an investigation in which we analyze the processes of asynchronous communication in forums of e-learning. In this research we have developed a system of categories that allows the analysis of the didactic interaction. We present this system, as well as the analysis of the data that we have obtained. We show the importance of attending to the elements of social, cognitive and didactics interaction so that the learning in virtual environments is developed in a more effective way

Do proactive and reactive causes to delete a brand impact deletion success? The role of brand orientation

Producción CientíficaOne critical decision concerning a firm´s brand portfolio management is brand deletion (BD). Although many organizations have recently undertaken drastic BD programs and pruned their brand portfolios, the literature on this topic remains extremely scarce and fragmented. Our work focuses on studying the impact of BD causes –previously classified as proactive versus reactive– on BD success. How the firm’s brand orientation affects the incidence of proactive versus reactive deletions is also explored. Implicitly, we suggest that brand orientation exerts a positive indirect effect on BD success through increased successful BDs due to proactive causes. We test our research proposal on a sample comprising 155 cases of BD. Findings indicate that brand orientation contributes to BD success through the proactive adoption of BDs focused on taking advantage of brand opportunities, such as searching for a better strategic fit or avoiding opportunity costs. Moreover, brand orientation prevents deletions by reactive or problematic causes, deletions which, after all, do not generate success. In sum, brand oriented firms seek to prevent rather than fix any problems derived from maintaining inadequate brands in their portfolio.Fondo Social Europeo (proyecto ORDEN EDU/828/2014)Junta de Castilla y León (ORDEN EDU/828/2014)Ministerio de Economía y Competetitividad (proyecto ECO2017-86628-P)Fondo europeo de desarrollo regional (proyecto VA112P17)Junta de Castilla y León (proyecto VA085G18

Comunicación y aprendizaje electrónico:la interacción didáctica en los nuevos espacios virtuales de aprendizaje

Este artículo presenta los resultados de una investigación en la que analizamos los procesos de comunicación asincrónica en foros de e-learning. En esta investigación hemos desarrollado un sistema de categorías que permite el análisis de la interacción didáctica. Presentamos dicho sistema, así como el análisis de los datos que hemos obtenido. Mostramos la importancia de atender a los elementos de comunicación social, cognitiva y didáctica para que el aprendizaje en contextos virtuales se desarrolle de manera más eficazThis article presents the results of a study where the processes of asynchronous communication in forums of e-learning are analysed.We have developed a system of categories which allows the analysis of the didactic interaction. On the other hand, we present both this system and the analysis of the data obtained. Finally,we show the importance of dealing with social, cognitive and didactic communication issues so that learning processes may be developed in more effective ways as regards virtual environment

Minimizing the negative impact of brand deletion

Producción CientíficaPurpose: This research is primarily concerned with studying the impact of brand workers' problems on brand deletion (BD) outcomes. The authors also analyze how the level of consensus achieved during BD adoption and implementation influences the impact of brand workers' problems on BD outcomes. Design/methodology/approach: A questionnaire was designed to obtain data from a representative sample of 155 real cases of BD. Findings: Findings indicate that in contexts where workers feel their jobs are threatened or challenged, BD success may be undermined. However, the company does possess one important mechanism that can alleviate the negative impact of brand workers' problems: empowering them to pave the way toward consensus-building. Results do not support a negative effect of brand workers' problems on BD time efficiency or any effect of BD time efficiency on BD's contribution to a firm's economic performance. Practical implications: Managers must be aware that problems derived from brand workers' actions are especially harmful for the company when there is no consensus, such that managers must prevent deletion from occurring under these circumstances. Originality/value: This pioneering study proposes and empirically validates the relationship between brand workers' problems and BD success and BD time efficiency, moderated by consensus.Junta de Castilla y León (Project VA219P20)Ministerio de Ciencia e Innovación (Project PID2021-123004NB-I00

Modeling an Aquifer: Numerical Solution to the Groundwater Flow Equation

We present a model of groundwater dynamics under stationary flow and governed by Darcy's Law of water motion through porous media, we apply it to study a 2D aquifer with water table of constant slope comprised of an homogeneous and isotropic media, the more realistic case of an homogeneous anisotropic soil is also considered. Taking into account some geophysical parameters we develop a computational routine, in the Finite Difference Method, that solves the resulting elliptic partial equation, both in a homogeneous isotropic and homogeneous anisotropic media. After calibration of the numerical model, this routine is used to begin a study of the Ayamonte-Huelva aquifer in Spain, a modest analysis of the system is given, we compute the average discharge vector as well as its root mean square as a first predictive approximation of the flux in this system, providing us a signal of the location of best exploitation; long term goal is to develop a complete computational tool for the analysis of groundwater dynamics.Comment: 13 pages and 12 figure