4,503 research outputs found
Introduction: Data Mining
La minería de datos es un campo multidisciplinario que combina estadísticas, aprendizaje automático, inteligencia artificial y tecnología de bases de datos
Influence of digital effects on consumer attitudes towards the advertisement and the brand
Los efectos digitales, incorporados durante la postproducción en publicidad audiovisual, son cruciales para potenciar la imagen de productos y marcas. Este estudio se enfocó en evaluar el impacto de los efectos digitales en las actitudes del consumidor, específicamente en la actitud hacia el anuncio (AA) y la actitud hacia la marca (AM). Utilizando un diseño cuasi experimental, se crearon dos spots publicitarios inicialmente idénticos; uno se modificó con la adición de efectos digitales, mientras que el otro se mantuvo sin cambios como elemento de control. Estos anuncios fueron presentados a un total de 346 personas a través de un medio en línea y posteriormente se aplicó una encuesta para medir sus reacciones. Se empleó análisis factorial confirmatorio, se aplicó prueba de Wilcoxon para comparar las respuestas entre los grupos. Los resultados muestran que las reacciones emocionales tienden a ser más positivas en los anuncios con efectos digitales, tanto para la actitud hacia el anuncio como para la actitud hacia la marca. Por lo tanto, se puede concluir que los efectos digitales cumplen un rol moderador en el desarrollo de actitudes hacia el anuncio y la marca. Sin embargo, la influencia de los efectos digitales es más pronunciada en la actitud hacia el anuncio.Digital effects, incorporated during post-production in audiovisual advertising, are crucial in enhancing the image of products and brands. This study focused on evaluating the impact of digital effects on consumer attitudes, specifically on attitudes towards the advertisement (AA) and attitudes towards the brand (AB). Using a quasi-experimental design, two initially identical advertising spots were created; one was modified with the addition of digital effects while the other was left unchanged as a control element. These spots were presented to a total of 346 people via an online medium and a survey was subsequently applied to measure their reactions. Confirmatory factor analysis was used; the Wilcoxon test was applied to compare the responses between the groups. The results indicate that emotional reactions tend to be more positive in ads with digital effects, in both attitude towards the ad and attitude towards the brand. Accordingly, it can be posited that digital effects play a moderating role in the development of attitudes towards the advertisement and the brand. However, the influence of digital effects is more pronounced in the attitude towards the ad
The Evolution of a Practice in Trialectic Space: An Approach Inclusive of Norms and Performance.
Practice theory has lately taken a turn towards modelling the evolution of practices, which appear situated at the centre of the study of social action. I argue in this paper, following previous criticisms, that such centrality can be revised in order to better incorporate elements of agency and normativity, which are much determinant of the emergence and development of practices. The aim of this paper is to propose an alternative heuristic which advances on lefebvrean trialectics, in order to better account for process in the study of practices. For this I rely on previous concepts from anthropology and sociology, such as fetishisation, ritualisation and bricolage. A relevant case study is merely outlined in order to illustrate how such a conceptual framework can identify agencies and situate practices in relation to power structures and performance at an early stage within the research process.
Análisis de la caracterización de imágenes de lesiones melanocíticas mediante la regla ABCD usado técnicas de selección de atributos
Presentación realizada en el marco del Proyecto: PINV18-1199: Diagnóstico automático de lesiones melanocíticas asistido por computadora.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI
Hybridizing deep learning and neuroevolution : application to the spanish short-term electric energy consumption forecasting
Presentación realizada en el marco del Proyecto PINV18-661: Análisis de la eficiencia energética en edificios no residenciales mediante técnicas metaheurísticas y de inteligencia artificial.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI
Web browsing interactions inferred from a flow-level perspective
Desde que su uso se extendiera a mediados de los noventa, la web ha sido probablemente el servicio de Internet más popular. De hecho, muchos usuarios la utilizan prácticamente como sinónimo de Internet. Hoy en día los usuarios de la web utilizan una gran cantidad dispositivos distintos para acceder a ella desde ordenadores tradicionales a teléfonos móviles, tabletas, lectores de libros electrónicos o, incluso, relojes inteligentes. Además, los usuarios se han acostumbrado a acceder a diferentes servicios a través de sus navegadores web en vez de utilizar aplicaciones dedicadas a ello. Este es el caso, por ejemplo del correo electrónico, del streaming de vídeo o de suites ofimáticas (como la proporcionada por Google Docs). Como consecuencia de todo esto, hoy en día el tráfico web es muy complejo y el efecto que tiene en las redes es muy importante.
La comunidad científica ha reaccionado a esta situación impulsando muchos estudios que caracterizan la web y su tráfico y que proponen maneras de mejorar su funcionamiento.
Sin embargo, muchos estudios centrados en el tráfico web han considerado el tráfico de los clientes o los servidores en su totalidad con el objetivo de describirlo estadísticamente. En otros casos, se han introducido en el nivel de aplicación al centrarse en los mensajes HTTP. Pocos trabajos han buscado describir el efecto que las sesiones de un sitio web y las visitas a páginas web tienen en el tráfico de un usuario. No obstante, esas interacciones son las que el usuario experimenta al navegar y, por tanto, son las que mejor representan su comportamiento.
El trabajo que se presenta en esta tesis gira alrededor de esas interacciones y se enfoca especialmente en identificarlas en el tráfico de los usuarios.
Esta tesis aborda el problema desde una perspectiva a nivel de flujo. En otras palabras, el estudio que se presenta se centra en una caracterización del tráfico web obtenida para cada conexión mediante datos de los niveles de transporte y red, nunca mediante datos de aplicación. La perspectiva a nivel de flujo introduce ciertas limitaciones en las propuestas desarrolladas, pero lo compensa al permitir desarrollar sistemas escalables, fáciles de instalar en cualquier red y que evitan acceder a información de usuario que podría ser sensible.
En los capítulos de este documento se introducen varios métodos para identificar sesiones a sitios web y descargas de páginas web en el tráfico de los usuarios. Para desarrollar dichos métodos se ha caracterizado tráfico web capturado de varias formas: accediendo a páginas automáticamente, con la ayuda de voluntarios en un entorno controlado y en el enlace de la Universidad Pública de Navarra. Los métodos que presentamos se basan en parámetros a nivel de conexión como los tiempos de inicio y final de los flujos o las direcciones IP de servidor. Estos parámetros se emplean para encontrar conexiones relacionadas en el tráfico de los usuarios.
La validación de los resultados obtenidos con los distintos métodos ha sido complicada al no disponer de trazas etiquetadas correctamente que puedan usarse para verificar que las clasificaciones se han realizado de forma correcta.
Además, al no haber propuestas similares en la literatura científica ha sido imposible comparar los resultados obtenidos con los de otros autores. Por todo esto ha sido necesario diseña métodos específicos de validación que también se describen en este documento.
Ser capaces de identificar sesiones a sitios web y descargas de páginas web tiene aplicaciones inmediatas para administradores de red y proveedores de servicio ya que les permitiría recoger datos sobre el perfil de navegación de sus usuarios e incluso bloquear tráfico indeseado y dar prioridad al importante.
Además, las ventajas de trabajar a nivel de conexión se aplican especialmente en su caso. Por último, los resultados obtenidos a través de los métodos presentados en esta tesis podrían emplearse en diseñar esquemas capaces de clasificar el tráfico web dependiendo del servicio que lo haya producido ya que se podrían utilizar como parámetros de entrada las características de múltiples conexiones relacionadas.Since its use became widespread during the mid 1990s, the web has probably been the most popular Internet service. In fact, for many lay users, the web is almost a synonym for the Internet. Web users today access it from a myriad of different devices from traditional computers to smartphones, tablets, ebook readers and even smart watches. Moreover, users have become accustomed to accessing multiple different services through their web browsers instead of through dedicated applications. This is the case, for example, of e-mail, video-streaming or office suites (such as the one provided by Google Docs). As a consequence, web traffic nowadays is complex and its effect on the networks is very important.
The scientific community has reacted to this providing many works that characterize the web and its traffic and propose ways of improving its operation.
Nevertheless, studies focused on web traffic have often considered the traffic of web clients or servers as a whole in order to describe their particular performance, or have delved into the application level by focusing on HTTP messages.
Few works have attempted to describe the effect of website sessions and webpage visits on web traffic. Those web browsing interactions are, however, the elements of web operation that the user actually experiences and thus are the most representative of his behavior. The work presented in this thesis revolves around these web interactions with the special focus of identifying them in user traffic.
This thesis offers a distinctive approach in that the problem at hand is faced from a flow-level perspective. That is, the study presented here centers on a characterization of web traffic obtained on a per connection basis and using information from the transport and network levels rather than relying on deep packet inspection. This flow-level perspective introduces various constraints to the proposals developed, but pays off by offering scalability, ease of deployment, and by avoiding the need to access potentially sensitive application data.
In the chapters of this document, different methods for identifying website sessions and webpage downloads in user traffic are introduced. In order to develop those methods, web traffic is characterized from a connection perspective using traces captured by accessing the web automatically, with the help of voluntary users in a controlled environment, and captured in the wild from users of the Public University of Navarre. The methods rely on connection-level parameters such as start and end timestamps or server IP addresses in order to find related connections in the traffic of web users.
Evaluating the performance of the different methods has been problematic because of the absence of ground truth (labeled web traffic traces are hard to obtain and the labeling process is very complex) and the lack of similar research which could be used for comparison purposes. As a consequence, specific validation methods have been designed and they are also described in this document.
Identifying website sessions and webpage downloads in user traffic has multiple immediate applications for network administrators and Internet service providers as it would allow them to gather additional insight into their users browsing behavior and even block undesired traffic or prioritize important one.
Moreover, the advantages of a connection-level perspective would be specially interesting for them. Finally, this work could also help in research directed to classifying thee services provided through the web as grouping the connections related to the same website session may offer additional information for the classification process.Programa Oficial de Doctorado en Tecnologías de las Comunicaciones (RD 1393/2007)Komunikazioen Teknologietako Doktoretza Programa Ofiziala (ED 1393/2007
Object-Based Greenhouse Mapping Using Very High Resolution Satellite Data and Landsat 8 Time Series
Greenhouse mapping through remote sensing has received extensive attention over the last decades. In this article, the innovative goal relies on mapping greenhouses through the combined use of very high resolution satellite data (WorldView-2) and Landsat 8 Operational Land Imager (OLI) time series within a context of an object-based image analysis (OBIA) and decision tree classification. Thus, WorldView-2 was mainly used to segment the study area focusing on individual greenhouses. Basic spectral information, spectral and vegetation indices, textural features, seasonal statistics and a spectral metric (Moment Distance Index, MDI) derived from Landsat 8 time series and/or WorldView-2 imagery were computed on previously segmented image objects. In order to test its temporal stability, the same approach was applied for two different years, 2014 and 2015. In both years, MDI was pointed out as the most important feature to detect greenhouses. Moreover, the threshold value of this spectral metric turned to be extremely stable for both Landsat 8 and WorldView-2 imagery. A simple decision tree always using the same threshold values for features from Landsat 8 time series and WorldView-2 was finally proposed. Overall accuracies of 93.0% and 93.3% and kappa coefficients of 0.856 and 0.861 were attained for 2014 and 2015 datasets, respectively
Geometric thermodynamics: black holes and the meaning of the scalar curvature
In this paper we show that the vanishing of the scalar curvature of
Ruppeiner-like metrics does not characterize the ideal gas. Furthermore, we
claim through an example that flatness is not a sufficient condition to
establish the absence of interactions in the underlying microscopic model of a
thermodynamic system, which poses a limitation on the usefulness of Ruppeiner's
metric and conjecture. Finally, we address the problem of the choice of
coordinates in black hole thermodynamics. We propose an alternative energy
representation for Kerr-Newman black holes that mimics fully Weinhold's
approach. The corresponding Ruppeiner's metrics become degenerate only at
absolute zero and have non-vanishing scalar curvatures.Comment: LaTeX file, no figure
Digital factory for small- and medium-sized advanced transport companies
The project develops the concept and implementation of Industry 4.0 for small- and medium-sized companies, which is currently lacking in the industrial sector. The aim is to obtain a methodology or procedure to facilitate the conversion of medium-sized industrial manufacturing companies into “digital factory” working models, in accordance with Industry 4.0
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