1,739 research outputs found
Understanding the impact of line-of-sight in the ergodic spectral efficiency of cellular networks
In this paper we investigate the impact of lineof-sight (LoS) condition in the ergodic spectral efficiency of cellular networks. To achieve this goal, we have considered the kappa-mu shadowed model, which is a general model that provides an excellent fit to a wide set of propagation conditions. To overcome the mathematical complexity of the analysis, we have split the analysis between large and small-scale effects. Building on the proposed framework, we study a number of scenarios that range from heavily-fluctuating LoS to deterministic-LoS. Finally, we shed light on the interplay between fading severity and spectral efficiency by means of the amount of fading.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Improved wear performance of ultra high molecular weight polyethylene coated with hydrogenated diamond like carbon
Hydrogenated diamond like carbon (DLCH) thin films were deposited on medical grade ultra high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition. The DLCH coating thicknesses ranged from 250 to 700. nm. The substrates were disks made of UHMWPEs typically used for soft components in artificial joints, namely virgin GUR 1050 and highly crosslinked (gamma irradiated in air to 100. kGy) UHMWPEs. Mechanical and tribological properties under bovine serum lubrication at body temperature were assessed on coated and uncoated polyethylenes by means of nano-hardness and ball-on-disk tests, respectively. Morphological features of the worn surfaces were obtained by confocal microscopy and scanning electron microscopy. This study confirms an increase in surface hardness and good wear resistance for coated materials after 24. h of sliding test compared to uncoated polyethylene. These results point out that to coat UHMWPE with DLCH films could be a potential method to reduce backside wear in total hip and knee arthroplasties.Ministerio de Ciencia y Educación MAT2006-12603- C02-01, CSD2008-0002
Plan de negocio: MyWebMotor (Parte 1).
myWebMotor es un producto software desarrollo por el Departamento de "Desarrollo Software y Diseño Gráfico" de la joven empresa almeriense Grupo Almería Formación, SLL. La citada empresa posee varios departamentos, con sus propias líneas de negocio como: "Servicio a empresas" y "Formación". myWebMotor nace con la intención de ser el gestor de contenidos más fácil e intuitivo del mundo. Es el primer proyecto de este departamento. Se trata de una gran base de datos que va almacenando la información de los páginas Web de clientes, junto con la plantilla que las mostrará al visitar su Web. El usuario, que consulta cualquiera de estas páginas, lo que en realidad hace es sacar información de nuestra base de datos. Lo que nos diferencia de la competencia es la versatilidad que se le ofrece al administrador de la Web, dándole más libertad que nuestra competencia directa. La facilidad de uso es otro de nuestro potencial y, por último, pero no menos importante, sino más bien, lo que más, es la atención personalizada que damos, a través de nuestros distribuidores. Ahora mismo estamos en disposición de competir en precios, ya que somos los que tenemos el precio de mercado más bajo, en la facilidad de uso y la versatilidad. Nuestra misión es mejorar la rentabilidad de las empresas y el crecimiento de pequeñas y medianas empresas para ser un buen proveedor de soluciones por Internet. Trabajamos para equipar a cada dueño de negocio con la oportunidad de fortalecer su marca, incrementar el conocimiento de su mercado y mejorar la eficiencia operativa. Nuestra visión es conseguir que la gran mayoría de PYMES en el mundo usen myWebMotor como su herramienta para crear y mantener su Web corporativa. Tener distribuidores en todo el mundo nos facilitará dicha visión futura. La idea de negocio surge de la experiencia de uno de los socios, haciendo páginas Web para empresas que pronto quedaban obsoletas debido a que en éstas no existía personal cualificado para modificarlas. Con este gestor de contenidos esos problemas ya no existen, debido a que cualquier persona, con conocimientos básico de un procesador de textos, puede ser el administrador de la web. A corto plazo, tenemos los siguientes objetivos: Seguir mejorando myWebMotor para suplir las deficiencias que tiene con respecto a la competencia, a la vez que incorporan herramientas innovadores, que mejores la diferenciación de nuestro producto. ¡myWebMotor está en continua evolución y mejora! Dar soporte a nuestra red de distribuidores, para que se posiciones en el mercado con el mayor éxito y consigan una penetración en el mismo con nuestro gestor de contenidos. Captar la mayor cantidad de distribuidores a nivel mundial. Para ello, es indispensable el montar una infraestructura web que publicite myWebMotor y hacer un buen plan de Marketing. En el medio plazo, tenemos, como principal objetivo, la homologación para ser proveedor oficial de WSI a nivel mundial, como ya lo somos localmente. Las estrategias irán enfocadas, sobre todo, a las ventas y a la captación de los distribuidores. El equipo de trabajo inicial que se propone para la puesta en funcionamiento del negocio es el siguiente: en el Departamento Software tendremos un Director de área, un Director de Sistemas y dos Programadores. También contaremos con tres Comerciales, de venta directa, y tres Distribuidores externos. El responsable de RRHH, Administración y Contabilidad y una Auxiliar Administrativa, cerrarán la plantilla base. La inversiones requerida no es demasiado elevada, ya que el proyecto software nace en una empresa ya constituida y sólo requerirá la compra de material informático relacionado. La principal inversión será la que constituyan las nóminas de los trabajadores del proyecto. Dicha inversión se acometerá con capital propio al 100 %. Tras realizar un estudio con los principales indicadores de rentabilidad, como veremos en el capítulo 9, hemos podido comprobar la viabilidad tanto económica como financiera del proyecto. Todo ello corroborado con un estudio de mercado que avala dicha iniciativa, debido a la necesidad candente de este tipo de tecnologías y de que la empresa use Internet como herramienta de su día a día.Como conclusión, nos hemos fijado en cuáles son los principales descubrimientos que este Plan de Negocio ha desencadenado y serán tenidos en cuenta en el futuro desarrollo del producto. Podemos destacar: En el análisis comparativo de myWebMotor, frente a su competencia directa hemos advertido que la principal de ellas es la atención personalizada, la cercanía y el asesoramiento que podemos ofrecer, gracias a la venta a través de distribuidores. La realización del Análisis DAFO también ha enriquecido nuestra visión general del producto y el mercado. Como ejemplo, pensábamos que poseíamos diversas fortalezas, como precios más bajos, pero, realmente, nos hemos dado cuenta de que eran ventajas coyunturales, ya que tenemos mayores costes que la competencia. Una vez enfocada nuestra principal ventaja competitiva, pudimos plantear las acciones de marketing al destinatario objetivo: empresas distribuidoras de myWebMotor. En lo que respecta a los Recursos Humanos, hemos priorizado la formación de los distribuidores, para que estén en disposición de aportar nuestro valor añadido
Organizational learning and innovation as sources of strategic fit
Purpose
The purpose of this paper is to analyze the roles played by organizational learning (OL) and innovation in organizations immersed in the processes of adaptation and strategic fit in dynamic and turbulent environments. The authors analyze whether OL and innovation act as sources of strategic fit, and whether strategic fit positively affects performance.
Design/methodology/approach
The authors use data from a survey of a representative sample of 204 respondents from European firms active in high-technology sectors (response rate: 10.42 percent) and structural equation modeling (using the EQS 6.1 program) to undertake a transversal study.
Findings
The model confirms that OL and the capacity to innovate positively influence managers’ decisions to adapt their organizations to changes in dynamic environments. The achievement of strategic fit, in turn, improves organizational performance. The authors propose considering the innovation climate as a facilitator of new product and process development, although the innovation climate is not a direct antecedent of fit.
Research limitations/implications
This study is limited by the fact that the analysis is cross-sectional and by the fact that all measures used are based on managers’ perceptions.
Practical implications
Managers should create and support an entrepreneurial culture that stresses continuous learning. They should also foster programs aimed at developing abilities, and promote the development of capabilities that facilitate acceptance of organizational change. Investments in building certain capabilities, such as OL and the capacity to innovate, are strategically justified, especially in turbulent environments.
Originality/value
This study is one of the first to investigate the complex interactions among OL, innovation, strategic fit, and performance. The results improve our understanding of the links between strategic fit and performance
Impact on the Hipparcos2-UCAC4 geometric relation from some physical properties of the stars
[EN] The aim of this paper is the study of the impact that the consideration of different
physical properties as magnitude and spectral type of stars has on the geometric relations
between Hipparcos2 and UCAC4. In this sense, the pairs of residuals ¿¿
¿
and ¿¿ can be
considered as functions of (¿, ¿, r) and for each fixed r, we can fit a vector field on the sphere
from which to obtain its components in the VSH basis. The same can be done by grouping
the stars considering their magnitudes, spectral types (or mixing them) and then studying the
variations in the mentioned geometry. We must not forget that ¿¿
¿
and ¿¿ are numerical
random variables whose regression on the magnitude m, for example, can be estimated. The
results will be computed taking into account r as well as the physical mentionThis work was supported by a grant UJI-B2016-18Marco, FJ.; Martínez Uso, MJ.; López, JA. (2018). Impact on the Hipparcos2-UCAC4 geometric relation from some physical properties of the stars. Proceedings of the International Astronomical Union. 12(S330):237-238. https://doi.org/10.1017/S1743921317006457S23723812S330Marco F. J. , Martínez M. J. & López J. A. 2017, Astrometry and Astrophysics in the Gaia Sky, In Press
A 3D-Study of the residual vector field
[EN] One of the important challenges that Gaia imposes on the Astrometric Catalogs, is a careful study in everything affected by parallax. A particularly important case is the necessary linkage Gaia - HCRF - ICRF2, which require methods of analysis that are accurate enough so that the provided results are at the same precision level as the work data.This work was supported by a grant UJI-B2016-18Marco, FJ.; Martínez Uso, MJ.; López, JA. (2018). A 3D-Study of the residual vector field. Proceedings of the International Astronomical Union. 12(S330):235-236. https://doi.org/10.1017/S1743921317006536S23523612S33
Psychological elements explaining the consumer's adoption and use of a website recommendation system: A theoretical framework proposal
The purpose of this paper is to understand, with an emphasis on the psychological perspective of the research problem, the consumer's adoption and use of a certain web site recommendation system as well as the main psychological outcomes involved. The approach takes the form of theoretical modelling. Findings: A conceptual model is proposed and discussed. A total of 20 research propositions are theoretically analyzed and justified. Research limitations/implications: The theoretical discussion developed here is not empirically validated. This represents an opportunity for future research. Practical implications: The ideas extracted from the discussion of the conceptual model should be a help for recommendation systems designers and web site managers, so that they may be more aware, when working with such systems, of the psychological process consumers undergo when interacting with them. In this regard, numerous practical reflections and suggestions are presented
Cross-cultural adaptation, reliability, and validation of the Spanish perceived physical literacy instrument for adolescents (S-PPLI)
Objective: The aim of this study was to examine the reliability and validity of the Spanish Perceived
Physical Literacy Instrument (S-PPLI) questionnaire in Spanish adolescents.
Method: The participants of this study were 360 Spanish adolescents (aged 12-17 years) from three
secondary schools in the Region of Murcia (Spain). A cultural adaptation process of the original version of
the PPLI questionnaire was developed. Confirmatory factor analysis was applied to test the three-factor
structure of physical literacy. Intraclass correlation coefficients were computed to estimate the test-retest
concordance.
Results: Using a confirmatory factor analysis, the factor loading of all items above the standard of 0.40
ranged from 0.53 to 0.77, suggesting that the observed variables sufficiently represented the latent
variables. Analyses for convergent validity showed average variance extracted values that ranged from
0.40 to 0.52 and composite reliability values higher than 0.60. All the correlations were below the recommended cutoff point of 0.85, which indicated that the three physical literacy factors achieved
adequate discriminant validity. Intraclass correlation coefficients ranged from 0.62 to 0.79 (p < 0.001 for
all items), which indicated moderate/good reliability.
Conclusions: Our results suggest that the S-PPLI is a valid and reliable measure of physical literacy among
Spanish adolescents
Consumer’s trust in Internet shopping: a modelling proposal based on the standard learning hierarchy
This paper is placed on the framework of studies focused on analyzing the consumers’ buying behaviour on the Internet. We have based on adapting the hierarchy-of-effects model (standard learning hierarchy), in order to theoretically propose a conceptual model explaining how consumers’ beliefs i.e. design, interaction speed, social benefits, and privacy and attitudes toward the Internet as a communication medium can be plausible determinants of trusting in Internet shopping. Furthermore, our model poses that consumers’ overall opinions regarding with in-home shopping might also exert an influence on their evaluations about the Internet as a communication medium and, specially, as a shopping medium. The proposed conceptual model is supported by a deep and specific literature review. The relationships contained in the model have been estimated by means of structural equation modelling. Results confirm that this approach based on the cognitive information processing is valid to model consumers’ shopping behaviour on the Internet. Finally, several academic reflections, as well as a set of managerial implications based on the questions analyzed, are put forward.Online consumer behaviour, attitude, trust in Internet shopping, standard learning hierarchy.
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