732 research outputs found
How ubiquitous is ubiquitous communication? Assessing bandwidth distributions among 172 countries from 1986 to 2013
Any assessment of ubiquitous, intelligent and mobile communication networks has to start with an adequate assessment of the underlying infrastructure. As the digital age continues its evolution into the new paradigms of big data and smart things, the digital divide evolves with it. While the analysis of digital deprivation traditionally has focused on the number of telecommunication subscriptions, the current evolution is adding new dimensions to the challenge of digital equality. While end-user subscriptions like phones and internet connections are reaching a certain level of saturation, the divide in terms of bandwidth continues to unfold its surprising dynamics. In order to obtain a better understanding of this dynamic, this study quantifies global digital development for 172 countries from 1986 to 2013 in terms of three indicators: the number of telecom subscriptions (phones, internet, tablets and wearables); the corresponding bandwidth (in kbps, fixed and mobile, upload and download); and the equality of the arising distribution among and within countries. It shows that the divide in terms of end-user subscriptions is rapidly closing, while the divide in terms of bandwidth is far from being closed and is instead being converted into a permanent structural characteristic of modern societies. The reason is that installed bandwidth potential in terms of kbps per capita is closely linked to income per capita, which is characterized by a notoriously persistent inequality. Novel findings reveal that only 3 countries host 50 % of the globally installed bandwidth potential (10 countries 75 %) and that the contribution of mobile access solutions to global bandwidth is continuously fluctuating with incessant technological innovation, reaching almost 40 % in both 2001 and 2013, while falling to 16 % in 2007. In terms of inequality, we show that the digital divide between high- and low income countries in terms of kbps per capita has increased between 2001 and 2008, only decreasing below historic levels very recently during 2012-2013. Nevertheless, it is constantly increasing in absolute terms. In 2003, the average inhabitant of high income countries had access to 90 kbps more than the average inhabitant of the rest of the world (100 vs. 10 kbps). This divide increased with an order of magnitude every 5 years, reaching almost 900 kbps in 2007, and over 10,000 kbps by 2013. This increasing divide in absolute terms is important to notice in the context of a big data world, in which the amount of data is becoming a crucial ingredient for growth and development. We also estimate the distribution of digital equality within countries by using a worst-case approximation method. It shows that national inequality has increased between 1995 and 2009, which is surprising, considering the habitual talk about ubiquitous communication networks in the digital age. Our Gini coefficient within countries decreases only very recently, during the past three years. This shows that the adjective 'ubiquitous' is finally starting to convert from a mere promise into a tangible and quantifiable opportunity
The bad news is that the digital access divide is here to stay: Domestically installed bandwidths among 172 countries for 1986–2014
In contrary to the common argument that the digital access divide is quickly closing and that the focus should shift to skills and usage, this article shows that access to digital communication is a moving target unlikely to ever be solved. While the number of subscriptions reaches population saturation levels, the bandwidth divide continuous to be dynamic. The article measures the nationally installed bandwidth potential of 172 countries from 1986 to 2014. The overarching finding is that the divide in terms of bandwidth does not show any clear monotonic pattern. It fluctuates up and down over the decades as the result of an intricate interplay between incessant technological progress and diffusion of technology. The bandwidth divide between high- and low income countries has first increased and only decreased below historic levels very recently during 2012-2014. In general it shows that the bandwidth divide is linked to the income divide, which is notoriously persistent. The bandwidth distribution among all countries is undergoing a new process of global concentration, during which North America and Europe is being replaced by Asia as the new global leader. In 2014 only 3 countries host 50 % of the globally installed bandwidth potential (10 countries almost 75 %). The U.S. lost its global leadership in 2011, being replaced by China, which contributes more than twice as much national bandwidth potential in 2014 (29 % versus 13 %). Despite this bad news about the continuous persistence of the digital access divide among countries, exploratory analysis from a global perspective brings the good news that many more individual people seem to enjoy more equal access to global bandwidth. All of this showcases the urgency to systematically develop indicators to track the digital divide in terms of bandwidth
Formal definitions of information and knowledge and their role in growth through structural change
The article provides a way to quantify the role of information and knowledge in growth through structural adjustments. The more is known about environmental patterns, the more growth can be obtained by redistributing resources accordingly among the evolving sectors (e.g. bet-hedging). Formal equations show that the amount of information about the environmental pattern is directly linked to the growth potential. This can be quantified by treating both information and knowledge formally through metrics like Shannon's mutual information and algorithmic Kolmogorov complexity from information theory and computer science. These mathematical metrics emerge naturally from our evolutionary equations. As such, information becomes a quantifiable ingredient of growth. The policy mechanism to convert information and knowledge into growth is structural adjustment. The presented approach is applied to the empirical case of U.S. export to showcase how information converts into growth potential
Centros de acceso público a las tecnologías de información y comunicación en América Latina: características y desafíos
Incluye BibliografíaEl objetivo principal del presente estudio, fue identificar y caracterizar el mayor número posible de programas de Centros de Acceso Público a las Tecnologías de la Información y Comunicación (CAPT), existentes en los países seleccionados para el estudio. El resultado del mismo es un mapeo que debe ser entendido como una primera aproximación a la situación actual. En este sentido, el levantamiento no proclama ser exhaustivo, ni completo, o estadísticamente representativo, sino un primer paso en un terreno todavía bastante desconocido, pero de crucial importancia para el desarrollo de las Sociedades de la Información en América Latina (AL). No obstante, cabe mencionar que, de acuerdo con la literatura revisada, este estudio es el más extenso y profundo sobre esta temática realizado en la región hasta la fecha. En el marco del estudio, se realizaron un total de 70 entrevistas válidas a responsables de los programas CAPT existentes en la región, en un total de 13 países. La información coleccionada a través de este mecanismo esta definida como fuente primaria (FP). Adicionalmente se recabó información secundaria sobre 151 programas CAPT adicionales (fuente secundaria FS). El estudio está dividido en dos partes: la primera parte muestra los resultados cuantitativos sobre el fenómeno de los CAPT en 14 países de la región de América Latina. Brasil fue incluido en la muestra del estudio, aunque solo se pudo obtener información secundaria. La segunda parte presenta los análisis cualitativos realizados por los investigadores responsables de la realización de las entrevistas. Los resultados de la primera parte muestran como el fenómeno de los CAPT presenta una evolución creciente y con altas perspectivas de sostenibilidad en el tiempo. El estudio, permite tener un primer acercamiento a la realidad de los CAPT a través del análisis del centro promedio y formular algunas recomendaciones que contribuyan al mejoramiento de este tipo de iniciativas. De acuerdo con datos anteriormente disponibles (ver por ejemplo CEPAL, 2005) se estimaba que en 2004 el número de CAPT gubernamentales oscilaba entre 6.000 y 10.000 en toda América Latina. Los resultados obtenidos mediante investigaciones primarias y secundarias de este nuevo sondeo, indican que para el año 2005 el número total de CAPT, tanto gubernamentales como privados, ascendían a 139.064 y se prevee que este número se incremente en años sucesivos
Anomalous Microwave Surface Resistance of CeCu6
We present surface resistance measurements of the archetypical heavy-fermion
compound CeCu6 for frequencies between 3.7 and 18 GHz and temperatures from 1.2
to 6 K. The measurements were performed with superconducting stripline
resonators that allow simultaneous measurements at multiple frequencies. The
surface resistance of CeCu6 exhibits a pronounced decrease below 3 K, in
consistence with dc resistivity. The low-temperature frequency dependence of
the surface resistance follows a power law with exponent 2/3. While for
conventional metals this would be consistent with the anomalous skin effect, we
discuss the present situation of a heavy-fermion metal, where this frequency
dependence might instead stem from the influence of electronic correlations.Comment: 6 pages, 3 figures, proceedings of SCES 201
Panorama digital 2007 de América Latina y el Caribe: avances y desafíos de las políticas para el desarrollo con las tecnologías de información y comunicaciones
Incluye BibliografíaEste estudio es un inventario de Estrategias Nacionales e iniciativas sectoriales de los países de América Latina y el Caribe en torno a la Sociedad de la Información (SI). Pretende contribuir a entender mejor las situaciones que enfrentan los países de América Latina y el Caribe en su transición hacia la Sociedad de la Información en el año 2007.El reporte es el resultado de un esfuerzo conjunto del PNUD (Programa de las Naciones Unidas para el Desarrollo), la CEPAL (Comisión Económica para América Latina y el Caribe de las Naciones Unidas), DIRSI (Diálogo Regional sobre Sociedad de la Información y el ICAIDRC (Instituto para la Conectividad en la Américas del Centro Internacional de Investigaciones para el Desarrollo) por estudiar los avances y desafíos de las políticas digitales en 21 países de la región. La iniciativa responde a la demanda de los países en su actual Plan de Acción Regional (eLAC2010), específicamente a la meta 60, en que las autoridades apuntan a "Fortalecer las políticas nacionales para la sociedad de la información desde una perspectiva regional, incluidas la coordinación y participación de organismos públicos, la sociedad civil y el sector privado y académico, dentro de sus respectivos roles y responsabilidades en el diseño y la difusión de programas sobre las TIC."El estudio está estructurado en cuatro grandes partes. La primera busca presentar el contexto de la transición hacia la Sociedad de la Información de los países de América Latina y el Caribe, caracterizado por la llamada brecha digital. En este punto se destaca el hecho que la frontera tecnológica es un blanco móvil, desplazándose con el surgimiento de nuevas Tecnologías de Información y Comunicaciones (TIC), y que la misma presenta tres dimensiones: de acceso a las TIC, de calidad en cuanto al acceso, y de uso de dichas tecnologías. Esta distinción es relevante, en la medida que si bien se observa un avance en términos de reducción de esta brecha en cuanto al acceso a la telefonía móvil, la brecha en la conectividad a nuevas tecnologías con mayor calidad de transmisión, como Internet de banda ancha, lejos de reducirse, está en expansión. Esto asociado a que en los países de la región aún se hace un uso limitado de las TIC, en sentido que éstas no son incorporadas plenamente a las actividades productivas y sociales a través de la digitalización de procesos, lo que restringe el aprovechamiento del potencial de estas tecnologías para el desarrollo social y económico
Flatness and Monge parameterization of two-input systems, control-affine with 4 states or general with 3 states
This paper studies Monge parameterization, or differential flatness, of
control-affine systems with four states and twocontrols. Some of them are known
to be flat, and this implies admitting a Monge parameterization. Focusing on
systems outside this class, we describe the only possible structure of such a
parameterization for these systems, and give a lower bound on the order of this
parameterization, if it exists. This lower-bound is good enough to recover the
known results about "(x,u)-flatness" of these systems, with much more
elementary techniques
Learning Universal Computations with Spikes
Providing the neurobiological basis of information processing in higher animals, spiking neural networks must be able to learn a variety of complicated computations, including the generation of appropriate, possibly delayed reactions to inputs and the self-sustained generation of complex activity patterns, e.g. for locomotion. Many such computations require previous building of intrinsic world models. Here we show how spiking neural networks may solve these different tasks. Firstly, we derive constraints under which classes of spiking neural networks lend themselves to substrates of powerful general purpose computing. The networks contain dendritic or synaptic nonlinearities and have a constrained connectivity. We then combine such networks with learning rules for outputs or recurrent connections. We show that this allows to learn even difficult benchmark tasks such as the self-sustained generation of desired low-dimensional chaotic dynamics or memory-dependent computations. Furthermore, we show how spiking networks can build models of external world systems and use the acquired knowledge to control them
“La etapa de evolución social en la que nos encontramos ya está fusionada con la inteligencia artificial, mucho más allá de cualquier punto de retorno”. Entrevista al Dr. Martin Hilbert
Martin Hilbert is, without a doubt, one of the most outstanding researchers of recent times. From his multidisciplinary works published in scientific journals of great impact and trajectory, he has made it possible for us to understand the information society more completely. Hilbert has worked for different international organizations and is particularly interested in the role of information or big data in complex social systems. Disciple of Manuel Castells, and currently, he is an associate professor in the Communications Department of the University of California. With this interview, we wanted to delve into the way in which Hilbert sees the impact of digitalization in areas such as economics, research, politics, social sciences and humanity, in general.Martin Hilbert es, sin lugar a dudas, uno de los más destacados investigadores de los últimos tiempos. Desde sus trabajos multidisciplinarios publicados en revistas científicas de gran impacto y trayectoria, nos ha hecho posible entender a la sociedad de la información de manera más íntegra. Hilbert ha trabajado para distintos organismos internacionales y se interesa particularmente en el rol de la información o big data en sistemas sociales complejos. Discípulo de Manuel Castells, y actualmente, es profesor asociado en el Departamento de Comunicaciones de la Universidad de California. Con esta entrevista, hemos querido ahondar en la forma en que Hilbert ve el impacto de la digitalización en ámbitos como la economía, la investigación, la política, las ciencias sociales y la humanidad, en general
- …