847 resultados para ponderomotive broadening


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We present a theory which permits for the first time a detailed analysis of the dependence of the absorption spectrum on atomic structure and cluster size. Thus, we determine the development of the collective excitations in small clusters and show that their broadening depends sensitively on the tomic structure, in particular at the surface. Results for Hg_n^+ clusters show that the plasmon energy is close to its jellium value in the case of spherical-like structures, but is in general between w_p/ \wurzel{3} and w_p/ \wurzel{2} for compact clusters. A particular success of our theory is the identification of the excitations contributing to the absorption peaks.

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The question of how shape is represented is of central interest to understanding visual processing in cortex. While tuning properties of the cells in early part of the ventral visual stream, thought to be responsible for object recognition in the primate, are comparatively well understood, several different theories have been proposed regarding tuning in higher visual areas, such as V4. We used the model of object recognition in cortex presented by Riesenhuber and Poggio (1999), where more complex shape tuning in higher layers is the result of combining afferent inputs tuned to simpler features, and compared the tuning properties of model units in intermediate layers to those of V4 neurons from the literature. In particular, we investigated the issue of shape representation in visual area V1 and V4 using oriented bars and various types of gratings (polar, hyperbolic, and Cartesian), as used in several physiology experiments. Our computational model was able to reproduce several physiological findings, such as the broadening distribution of the orientation bandwidths and the emergence of a bias toward non-Cartesian stimuli. Interestingly, the simulation results suggest that some V4 neurons receive input from afferents with spatially separated receptive fields, leading to experimentally testable predictions. However, the simulations also show that the stimulus set of Cartesian and non-Cartesian gratings is not sufficiently complex to probe shape tuning in higher areas, necessitating the use of more complex stimulus sets.

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IntraCavity Laser Absorption Spectroscopy (ICLAS) is a high-resolution, high sensitivity spectroscopic method capable of measuring line positions, linewidths, lineshapes, and absolute line intensities with a sensitivity that far exceeds that of a traditional multiple pass absorption cell or Fourier Transform spectrometer. From the fundamental knowledge obtained through these measurements, information about the underlying spectroscopy, dynamics, and kinetics of the species interrogated can be derived. The construction of an ICLA Spectrometer will be detailed, and the measurements utilizing ICLAS will be discussed, as well as the theory of operation and modifications of the experimental apparatus. Results include: i) Line intensities and collision-broadening coefficients of the A band of oxygen and previously unobserved, high J, rotational transitions of the A band, hot-band transitions, and transitions of isotopically substituted species. ii) High-resolution (0.013 cm-1) spectra of the second overtone of the OH stretch of trans-nitrous acid recorded between 10,230 and 10,350 cm-1. The spectra were analyzed to yield a complete set of rotational parameters and an absolute band intensity, and two groups of anharmonic perturbations were observed and analyzed. These findings are discussed in the context of the contribution of overtone-mediated processes to OH radical production in the lower atmosphere.

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The implementation of anti-drug policies that focus on illicit crops in the Andean countries faces many significant obstacles, one of which is the cultural clash it generates between the main stakeholders. On the one hand one finds the governments and agencies that attempt to implement crop substitution and eradication policies and on the other the peasant and natives communities that have traditionally grown and used coca or those peasants who have found in coca an instrument of power and political leverage that they never had before. The confrontation about coca eradication, alternative development and other anti-drug policies in coca growing areas transcends drug related issues and is part of a wider and deeper confrontation that reflects the long-term unsolved conflicts of the Andean societies. All Andean countries have stratified and fragmented societies in which peasants and Indians have been excluded from power. In Bolivia, Ecuador and Peru most peasants belong to native communities many of which have remained segregated from “white” society. The mixing of the races (mestizaje) in Colombia occurred early during the Conquest and Colony. Those of Indian descent became subservient to the Spanish and Creoles. The society that evolved was (and still is) highly hierarchical, authoritarian, and has subjacent racist values. The resulting political system has been exclusionary of large portions of the population. Among Indian communities coca has been used for millennia and its use has become an identity symbol of their resistance against what may be looked at as foreign invasion. “The Andean Indian chews coca because that way he affirms his identity as son and owner of the land that yesterday the Spaniard took away and today the landowner keeps away from him. To chew coca is to be Indian...and to quietly and obstinately challenge the contemporary lords that descend from the old encomenderos and the older conquistadors” (Vidart, 1991: 61, author’s translation). In Andean literature on illegal drugs as well as in seminars, colloquia and other meetings where drug policies are debated, complaints are frequently expressed about the treatment of coca in the same category as cocaine, heroin, morphine amphetamines and other “hard” drugs. The complainants assert that “coca is not cocaine” and that it is unfair to classify coca, a nature given plant which has been used for millennia in the Andes without significant negative effects on users, in the same category as man made psychotropic drugs. They also argue that coca has manifold social and religious meanings in indigenous cultures, that coca is sacred and that the requirement of the1961 Single Convention demanding that Bolivia and Peru completely eradicate coca within 25 years is limiting Indigenous communities in their freedom to practice their religions. In most debates about drug interdiction, the views of those who oppose that approach are not accepted as legitimate. Indeed, “prohibitionists” demonize drugs and those who oppose drug policies in Latin America frequently demonize the United States as the imperialist power that imposes them. This dual polarization is a main obstacle to establish a meaningful policy debate aimed at broadening the policy consensus necessary for successful policy implementation. This essay surveys the status of coca in the United Nations Conventions, explains why it is confusing, and how a few changes would eliminate some of the sources of conflict and help organize and control licit coca markets in the Andes. The current disorganized and weakly controlled legal coca market in Peru has been analyzed to demonstrate its deficiencies and to illustrate possible improvements in international drug control policies.

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The study examines how, from the traditional work of the independent artisan, we have moved to autonomous work integrated within networks of specialized businesses. This modality is owed not only to the manner in which labor is organized today, to government stimuli, to actions of multilaterals, but also to unemployment. With the purpose of humanizing independent work and rationalizing business costs, an intermediate category of autonomous worker has been created; the semi-dependent who moves between legal freedom and economic independence. The administration, for its part, focuses on broadening social coverage, not always developed for bureaucratic reasons, which is connected to the low density of contributions from the autonomous workers. The challenge put forth is that of provisional coverage for the independents, which is possible whenever citizens participate to resolve social inequality, resulting from the lack of job opportunities, low purchasing power and educational level. 

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Esta tesis pretende describir la situación actual del sector de seguridad privada, al implementar y adoptar estrategias de CRM. Con una revisión confiable y el estudio de casos relacionados con el tema, lo cual permitirá constatar la realidad en cuanto la aplicación del modelo, en el sector de seguridad privada, según lo planteado por diversos autores. Los resultados obtenidos permitirán, de este modo, al sector y a sus gerentes, desarrollar estrategias que ayuden a la satisfacción de sus clientes y a la prestación de un mejor servicio. En el campo académico, este estudio servirá como guía teórico-práctica para estudiantes y profesores, de modo que permitirá afianzar conocimientos en cuanto al CRM, al marketing relacional y su uso en el sector de seguridad privada. Según este modelo la información acerca de los clientes, es una información estratégica vital para las organizaciones que ayuda a la toma de decisiones, pronosticar cambios en cuanto a demanda, además de establecer control sobre procesos en los que se involucre el cliente; de modo que la adopción e implementación de CRM, ayude a la empresa, en este caso a las del sector de seguridad privada, a estar atentos a la manera como se interactúa con el cliente y por ende mejorar el servicio, lo que tendrá repercusión en la percepción que tenga de la organización el cliente. De este modo, se ve como en la actualidad las estrategias de CRM definen el rumbo de una empresa, ayudando atraer nuevos clientes y además de esto, ayuda de igual modo a mantener felices a los clientes actuales; lo cual repercute en la demanda o el requerimiento del servicio, y así en una mejor rentabilidad para las empresas del sector. Razones por las que el sector de vigilancia se verá beneficiado por medio de las estrategias del CRM, lo que lo llevara a ofrecer mejores servicios a sus clientes.

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De allí, que sea necesario analizar por qué las enfermedades infecciosas pueden constituir una amenaza a la seguridad desde un concepto más amplio como lo es el de la seguridad humana. Esta perspectiva permite ir más allá de la amenaza pura del bioterrorismo para dar cabida a los riesgos naturales

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Desde el inicio de su primera gestión presidencial, en el año 2002, el presidente Álvaro Uribe Vélez convirtió el concepto de Seguridad Democrática en un término recurrente para invocar una política de seguridad que legitimara la acción del Estado contra las principales amenazas identificadas por los colombianos: el terrorismo (condensado en las Fuerzas Armadas Revolucionarias de Colombia, FARC - EP) y el narcotráfico. La presente investigación tiene como objetivo discutir si este discurso del presidente Álvaro Uribe Vélez que privilegia, entre los años 2002 y 2004, una política del miedo, fue una estrategia de marketing del miedo o fue una estrategia de profundización democrática.

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Este trabajo de grado propone identificar la utilidad de las relaciones estratégicas comunitarias y el marketing en la administración de negocios con clientes corporativos, también se toman en cuenta conceptos como el marketing organizacional y relacional, estos conceptos ayudan en la investigación a determinar relaciones estratégicas entre las empresas, y el beneficio que estas le generan a las corporaciones; para así fomentar la implementación de estas estrategias en a las empresas a nivel nacional e internacional, así mismo, identificar el concepto de comunidad que tienen los clientes corporativos y como este concepto se puede adaptar al entorno que los rodea. Con el fin de entender las funciones y características de un cliente corporativo, así como su comportamiento, los objetivos específicos de la investigación son describir las estrategias de marketing en la administración de negocios con clientes corporativos, determinar si existe el concepto de comunidad en la administración de negocios con clientes corporativos y determinar si se utilizan relaciones estratégicas comunitarias en la administración de negocios con clientes corporativos. La metodología que se planteó usar fue teórica-conceptual, teniendo en cuenta el marketing y las relaciones estratégicas comunitarias de los clientes corporativos. Llevando la investigación al ámbito de la gerencia y dirección, los resultados que se obtuvieron gracias a la investigación, ayudaran a potenciar la dirección de las empresas, donde se evalué la verdadera utilidad de las estrategias basadas en las relaciones comunitarias y marketing en los negocios con clientes corporativos. Las estrategias comunitarias y el marketing influencian de manera directa las relaciones de las compañias con sus clientes corporativos, debido a que marketing nos permite extender la relación y generar una utilidad a futuro entre ambas partes. De la investigación se concluye que las empresas que logran crear estrategias comunitarias y relaciones estrechas entre ellas, tienden a tener mejores utilidades en el largo plazo y ser empresas más sostenibles.

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The main theme of the ICTOP'94 Lisbon meeting is museum personnel training for the universal museum. At the very beginning it is important to identify what the notion universal museum can cover. It is necessary to underline the ambiguity of the term. On the one hand, the word 'universal' can be taken to refer to the variety of collected museum materials or museum collections, on the other hand it could refer to the efforts of the museum to be active outside the museum walls in order to achieve the integration of the heritage of a certain territory into a museological system. 'Universal' could also refer to the "new dimensions of reality: the fantastic reality of the virtual images, only existing in the human brain" (Scheiner 1994:7), which is very close to M. McLuhan's view of the world as a 'global village'. Thus, what is universal could be taken as being common and available to all the people of the world. 'Universal' can imply also the radical broadening of the concept of object: "mountain, silex, frog, waterfonts, stars, the moon ... everything is an object, with due fluctuations" (Hainard in Scheiner 1994: 7), which will cause the total involvement of the human being into his/her physical and spiritual environment. In the process of universalization, links between cultural and natural heritage and their links with human beings become more solid, helping to create a strong mutual interdependence.

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