7 resultados para Rejection by peers
em Universidad Politécnica de Madrid
Resumo:
This work highlights two critical taboos in organizations: 1)taking for granted the quality of certain capabilities and attitudes of the end-user representatives (EUR) in information systems development projects (ISDP), and 2) the EUR´s inherent accountability for losses in IS investments. These issues are neither addressed by theory nor research when assessing success/ failure. A triangulation approach was applied to combine quantitative and qualitative methods, having convergent results and showing that in problematic cases, paradoxically, the origin of IS rejection by end users (EU) points towards the EUR themselves. It has been evaluated to what extent some EUR factors impacted a macro ISDP involving an enterprise resource planning (ERP) package, ranking the ‘knowledge of the EUR’ as the main latent variable. The results validate some issues found throughout decades of praxis, confirming that when not properly managed the EUR role by itself has a direct relationship with IS rejection and significant losses in IS investments.
Resumo:
La idea de este proyecto es acercar la imagen de Libertad de Información y su conocida variante Open Source, donde cubriremos en detalle la multitud de puntos que abarca. Está dirigida a todos los usuarios que quieran conocer de primera mano cómo se inició la idea de Libertad Tecnológica hasta sus aplicaciones. No solo para aquellos que quieran emplearla, sino tambien para aquellos que la ya la usan y necesitan recursos para nuevas ideas. De esta forma, nos acercaremos tambien a la idea de libertad que en la tecnología está actualmente en debate. El contenido se estructura siguiendo las siguientes ramas: Historia, desde sus orígenes hasta el presente. Economía, ventajas y desventajas de esta libertad. Problemas legales en distintos niveles Noticias y actualizaciones de aplicaciones. Sociedad, entorno a la aceptación y rechazo por los usuarios, ademas de su influencia en la ética, educación e innovación. Aplicaciones, donde se incluirán la mayoría de las aplicaciones más conocidas en cada una de las ramas de Open Source. ---ABSTRACT---The topic finally chosen in the list of Professional Skills and Issues has been the Freedom of Information and its best known variant Open Source. We will try to cover in detail most of the points that includes history, economics, law, society and the various applications in which it have influenced. It allows all the public to see first-hand the term of Open Source, from its beginnings to applications. Not just for those who want to use it, but for those who already use it and want to find sources and new ideas. It will also get a step closer to the idea of Freedom of Information as currently being debated. The main branches are going to address: History, from its origins to the present. Economic, advantages and disadvantages of being free. Laws, problems in different continents at the legal level. News, latest in its various applications. Society, acceptance or rejection by the people, addition to the factors that influence as ethics, education, and arts innovation. Applications, where most try to include most current applications of each of the variants.
Resumo:
Several international studies have analyzed the acceptability of road pricing schemes by means of an attitude survey in combination with the results of a stated choice experiment using both a descriptive analysis and a discrete-choice model with binary choice (?accept? or ?not accept? the toll). However, the use of hybrid discrete choice models constitutes an innovative alternative for integrating subjective attitudes and perceptions deriving from the survey of attitudes with the more objective variables from the stated choice experiment. This paper analyzes the results of applying these models to measure the acceptability of interurban road pricing among different groups of stakeholders (road freight and passenger operators, highway concessionaires, and associations of private car users) with qualitatively significant opinions on road pricing measures. Our results show that hybrid models are better suited to explaining the acceptability of a road pricing scheme by different groups of stakeholders than a separate analysis of the survey of attitudes and a discrete-choice model applied on a stated choice experiment. A particular finding was that the strong psycho-social latent variable of the perception of fairness explains the rejection or acceptance of a toll scheme by road stakeholders.
Resumo:
Monte Carlo techniques, which require the generation of samples from some target density, are often the only alternative for performing Bayesian inference. Two classic sampling techniques to draw independent samples are the ratio of uniforms (RoU) and rejection sampling (RS). An efficient sampling algorithm is proposed combining the RoU and polar RS (i.e. RS inside a sector of a circle using polar coordinates). Its efficiency is shown in drawing samples from truncated Cauchy and Gaussian random variables, which have many important applications in signal processing and communications. RESUMEN. Método eficiente para generar algunas variables aleatorias de uso común en procesado de señal y comunicaciones (por ejemplo, Gaussianas o Cauchy truncadas) mediante la combinación de dos técnicas: "ratio of uniforms" y "rejection sampling".
Resumo:
Durante décadas y aun en la actualidad muchas organizaciones, a nivel mundial, continúan afrontando pérdidas significativas debido a fracasos parciales y totales respecto a sus inversiones en sistemas de información (SI), planteando serios retos a los niveles gerenciales y los profesionales de SI. Estadísticas alarmantes y décadas de experiencia en la praxis en el área de SI en diversas organizaciones llevan al autor a poner el énfasis en los usuarios finales internos (UF) que son designados como representantes (UFR) de sus pares en los proyectos de desarrollo de SI (PDSI) por considerarlos como factores influyentes de manera significativa en el problema. Particularmente, con enfoque en ciertos factores de los UFR críticos para el éxito de los PDSI, con dimensiones analizadas de forma aislada o incompleta en otros estudios empíricos, a la fecha. No se encontraron estudios en Latinoamérica ni en otras latitudes que abordasen el fenómeno del éxito/fracaso de los SI desde el punto de vista adoptado en esta tesis. Por ello, esta investigación empírica ha evaluado en qué grado estos factores pudiesen influenciar los resultados durante el desarrollo e implementación de SI y su posible impacto en la satisfacción de los UF, siendo esta última aceptada por variados autores como la principal medida del éxito de los SI. Este estudio fue realizado en América Latina en las cuatro grandes empresas industriales que integran verticalmente el sector aluminio de Venezuela, sometidas a un macro PDSI para instalar el paquete, de tipo ERP, SAP/R3. Experimentados profesionales fueron encuestados o entrevistados, tales como altos ejecutivos, desarrolladores, líderes de proyecto y líderes de los UF. Un enfoque metodológico de triangulación permitió combinar un análisis cuantitativo con un análisis cualitativo interpretativo del tipo hermenéutico/dialéctico, hallándose resultados convergentes y complementarios. Un análisis estadístico, utilizando Partial Least Squares (PLS), seguido de un análisis hermenéutico/dialéctico. Los resultados confirmaron un hecho importante: en los casos problemáticos, paradójicamente, los orígenes de las razones de rechazo de esos SI argumentadas por los UF, en alto grado, apuntaron a los UFR o a ellos mismos. Los resultados también confirmaron la prevalencia de factores de orden cognitivo, conductual y político en estas organizaciones sobre los tecnológicos, al igual que el alto riesgo de dar por sentado la presencia y calidad de los factores requeridos de los UFR y de los otros factores estudiados. La validación estadística del modelo propuesto reveló al constructo conocimientos de los UFR como la principal variable latente, con los variables indicadoras que componen este constructo ejerciendo la mayor influencia sobre la calidad y el éxito de los SI. Un hallazgo contrario al de otros estudios, mostró que los conocimientos sobre las tecnologías de la información (TI) fueron los menos relevantes. Los SI de nómina y de administración de los RRHH fueron los más problemáticos, como suele ser el caso, por su complejidad en organizaciones grandes. Las conclusiones principales confirman el decisivo rol de los UF para el éxito de los PDSI y su relación con la creciente problemática planteada, la cual amerita más investigación y de las organizaciones una mayor atención y preparación. Descuidar los factores humanos y sociales así como una efectiva planificación y gestión de los mismos en preparación para estos proyectos origina serios riesgos. No obstante las limitaciones de este trabajo, la problemática analizada suele influir en los PDSI en diversas organizaciones, indistintamente de su tamaño o tipo de SI, estimándose, por tanto, que los resultados, conclusiones y recomendaciones de esta investigación tienen un alto grado de generalización. Una relación de indicadores claves es suministrada con fines preventivos. Finalmente, los factores evaluados pueden usarse para ampliar el modelo reconocido de DeLone y McLean (2003), conectándolos como variables latentes de sus variables independientes calidad de la información y calidad del SI. ABSTRACT For decades, many organizations worldwide have been enduring heavy losses due to partial and total failures regarding their investments in information systems (IS), posing serious challenges to all management levels and IS practitioners. Alarming statistics in this regard and decades of practice in the IS area lead the author to place an emphasis on the end users (EU) who are appointed in representation of their peers (EUR) to IS development projects (ISDP), considering them as highly influential factors on the problem. Especially, focusing on certain EUR success factors, and their dimensions, deemed critical to any IS development and implementation, omitted or not thoroughly analyzed neither in the theory nor in the empirical research on the subject, so far. No studies were found in Latin America or elsewhere addressing the phenomenon of IS success/failure from the perspective presented herein. Hence, this empirical research has assessed to what degree such factors can influence the outcomes of an ISDP and their feasible impact on the EU´s satisfaction, being the latter accepted by several authors as the main measure of IS success. This study was performed in Latin America embracing four major industrial enterprises, which vertically integrate the aluminum sector of Venezuela, subjected to a macro ISDP to install the ERP-type package SAP/R3. The field work included surveying and interviewing experienced professionals such as IS executives, IS developers, IS project leaders and end-user project leaders. A triangulation methodological approach allowed combining quantitative and interpretive analyses, obtaining convergent and complementing results. A statistical analysis, using Partial Least Squares (PLS), was carried out followed by a hermeneutical/dialectical analysis. Results confirmed a major finding: in problematic cases, paradoxically, the origins of IS rejection reasons argued by the EU, at a high degree, were usually traceable to the EUR and themselves. The results also confirmed the prevalence of cognitive, behavioral and political factors in these organizations as well as the high risk of taking for granted the presence and quality of those factors demanded from the EUR. The statistical validation of the proposed model revealed the construct EUR knowledge as the main latent variable, with its items exerting a major influence on IS quality and success. Another finding, in contradiction with that of other studies, proved knowledge of information technology (IT) aspects to be irrelevant. The payroll and the human resources administration IS were the most problematic, as is usually the case in large companies. The main conclusions confirm the EU´s decisive role for IS success and their relationship with the problem, which continues, demanding more research and, from organizations, more attention and preparation. Neglecting human and social factors in organizations as well as their effective planning and management in preparation for ISDP poses serious risks. Despite the limitations of this work, the analyzed problem tends to influence ISDP in a wide range of organizations; regardless of their size or type of IS, thus showing a high degree of generalization. Therefore it is believed that the results, conclusions and suggestions of this research have a high degree of generalization. A detailed checklist comprising key measures is provided for preventive actions. Finally, the factors evaluated can be used to expand the well-known model of DeLone & McLean (2003), by connecting them as latent variables of its independent variables information quality and IS quality.
Resumo:
Adaptive Rejection Metropolis Sampling (ARMS) is a wellknown MCMC scheme for generating samples from onedimensional target distributions. ARMS is widely used within Gibbs sampling, where automatic and fast samplers are often needed to draw from univariate full-conditional densities. In this work, we propose an alternative adaptive algorithm (IA2RMS) that overcomes the main drawback of ARMS (an uncomplete adaptation of the proposal in some cases), speeding up the convergence of the chain to the target. Numerical results show that IA2RMS outperforms the standard ARMS, providing a correlation among samples close to zero.
Resumo:
On-line partial discharge (PD) measurements have become a common technique for assessing the insulation condition of installed high voltage (HV) insulated cables. When on-line tests are performed in noisy environments, or when more than one source of pulse-shaped signals are present in a cable system, it is difficult to perform accurate diagnoses. In these cases, an adequate selection of the non-conventional measuring technique and the implementation of effective signal processing tools are essential for a correct evaluation of the insulation degradation. Once a specific noise rejection filter is applied, many signals can be identified as potential PD pulses, therefore, a classification tool to discriminate the PD sources involved is required. This paper proposes an efficient method for the classification of PD signals and pulse-type noise interferences measured in power cables with HFCT sensors. By using a signal feature generation algorithm, representative parameters associated to the waveform of each pulse acquired are calculated so that they can be separated in different clusters. The efficiency of the clustering technique proposed is demonstrated through an example with three different PD sources and several pulse-shaped interferences measured simultaneously in a cable system with a high frequency current transformer (HFCT).