An Efficient Precoder Design for Multiuser MIMO Cognitive Radio Networks with Interference Constraints

We consider a linear precoder design for an underlay cognitive radio multiple-input multiple-output broadcast channel, where the secondary system consisting of a secondary base-station (BS) and a group of secondary users (SUs) is allowed to share the same spectrum with the primary system. All the transceivers are equipped with multiple antennas, each of which has its own maximum power constraint. Assuming zero-forcing method to eliminate the multiuser interference, we study the sum rate maximization problem for the secondary system subject to both per-antenna power constraints at the secondary BS and the interference power constraints at the primary users. The problem of interest differs from the ones studied previously that often assumed a sum power constraint and/or single antenna employed at either both the primary and secondary receivers or the primary receivers. To develop an efficient numerical algorithm, we first invoke the rank relaxation method to transform the considered problem into a convex-concave problem based on a downlink-uplink result. We then propose a barrier interior-point method to solve the resulting saddle point problem. In particular, in each iteration of the proposed method we find the Newton step by solving a system of discrete-time Sylvester equations, which help reduce the complexity significantly, compared to the conventional method. Simulation results are provided to demonstrate fast convergence and effectiveness of the proposed algorithm. 

Kinetics and coverage dependent reaction mechanisms of the copper atomic layer deposition from copper dimethylamino-2-propoxide and diethylzinc

Atomic layer deposition (ALD) has been recognized as a promising method to deposit conformal and uniform thin film of copper for future electronic devices. However, many aspects of the reaction mechanism and the surface chemistry of copper ALD remain unclear. In this paper, we employ plane wave density functional theory (DFT) to study the transmetalation ALD reaction of copper dimethylamino-2-propoxide [Cu(dmap)2] and diethylzinc [Et2Zn] that was realized experimentally by Lee et al. [ Angew. Chem., Int. Ed. 2009, 48, 4536−4539]. We find that the Cu(dmap)2 molecule adsorbs and dissociates through the scission of one or two Cu–O bonds into surface-bound dmap and Cu(dmap) fragments during the copper pulse. As Et2Zn adsorbs on the surface covered with Cu(dmap) and dmap fragments, butane formation and desorption was found to be facilitated by the surrounding ligands, which leads to one reaction mechanism, while the migration of ethyl groups to the surface leads to another reaction mechanism. During both reaction mechanisms, ligand diffusion and reordering are generally endothermic processes, which may result in residual ligands blocking the surface sites at the end of the Et2Zn pulse, and in residual Zn being reduced and incorporated as an impurity. We also find that the nearby ligands play a cooperative role in lowering the activation energy for formation and desorption of byproducts, which explains the advantage of using organometallic precursors and reducing agents in Cu ALD. The ALD growth rate estimated for the mechanism is consistent with the experimental value of 0.2 Å/cycle. The proposed reaction mechanisms provide insight into ALD processes for copper and other transition metals.

Hydrothermale Dolomitisierung im Kauffunger Kalkstein (Paläozoikum - W-Sudeten, Polen

Within the Kauffung Limestone dolomite bodies related to volcanic contacts occure and are interpreted as a post-Variscan, hydrothermal volcanogenic formation. Two genetic dolomite types are discernible: a pervasive replacement saddle dolomite and a cavity filling saddle dolomite cement. Micro texture and oxygen isotopy of both dolomite types refer to heightened temperatures of formation. The ocurrence of the dolomite in contact to cross-cutting rhyolithic dikes points to a close petrogenetic relation. Dolomite bodies and rhyolithic injections in contrast to the rock wall are characterized by a distinctive cavernous texture, so that a prekinematic genesis is excluded. The formation of replacement saddle dolomite and saddle dolomite cement altogether are considered as a concomitant phenomenon of the Permo-Carboniferous volcanism widespread in the Bober-Katzbach Mountains.

Dramaturgia do aqui e agora: presença, recepção e sentido no corpo do ator

The actor is an actor during all the phases of creation and development of his character. (S) He goes beyond the moment of interpreting. In this sense, in her (his) daily life, the actor may use her (his) potential to extract from reality the necessary elements for the work of creation. This is a theoretical research which focus on the concept of presence in the actor s work, stretching the concept beyond the scene, encompassing different components such as the body, the word, the silence, the technique and the acting as the actor s stance in regards to his own reality. The objective of such stance is to integrate him (her) self in the environment, balancing his (hers) inner life with the outside life flow. To reach this objective, the research drew theoretical resources from the concept of presence in the actor s work according to BROOK, BARBA, GROTOWSKI and MNOUCHKINE and the studies on reception theory in ISER, 1996; GUMBRECHT, 2010. Thus, the dialogue between reader and actor high lights both as receivers in this work. A practical description of a street theater Kamchàtka show, featured by the Kamchàtka Company is used as an example of the research on the presence. The elements localized in this show are: play, listening, word, silence, meaning, relationship with here and now and the effects of the said presence

A framework for better understanding drinking-water quality in Happy Valley-Goose Bay, Labrador: Implications for optimization and protection of municipally supplied water

This research project was driven by the recurring complaints and concerns voiced in the media by residents living in the Valley area of the community of Happy Valley-Goose Bay, Labrador. Drinking water in this town is supplied by two water treatment plants (a municipality treatment plant and a DND treatment plant), which use raw water from two different sources (groundwater from multiple wells versus surface water from Spring Gulch brook) and use two different processes of drinking-water treatment. In fact, the drinking water supplied in the Valley area has a unique distribution arrangement. To meet demand, the Valley area is served by a blend of treated waters from a storage reservoir (Sandhill reservoir), which is fed by both water treatment plants. Most of the time, treated water from the municipal treatment plant dominates in the mixture. As water travels through the distribution system and household plumbing, specific reactions can occur either in the water itself and/or at the solid–liquid interface at the pipe walls; this is strongly influenced by the physical and chemical characteristics of the water. These reactions can introduce undesirable chemical compounds and/or favor the growth of bacteria in the drinking water, causing the deterioration of the quality of water reaching the consumer taps. In the distribution system in general, these chemical constituents and bacteria may pose potential threats to health or the water’s aesthetic qualities (smell, taste or appearance). Drinking water should be not only safe, but also palatable.

A bistable reaction-diffusion system in a stretching flow

We examine the evolution of a bistable reaction in a one-dimensional stretching flow, as a model for chaotic advection. We derive two reduced systems of ordinary differential equations (ODEs) for the dynamics of the governing advection-reaction-diffusion partial differential equations (PDE), for pulse-like and for plateau-like solutions, based on a non-perturbative approach. This reduction allows us to study the dynamics in two cases: first, close to a saddle-node bifurcation at which a pair of nontrivial steady states are born as the dimensionless reaction rate (Damkoehler number) is increased, and, second, for large Damkoehler number, far away from the bifurcation. The main aim is to investigate the initial-value problem and to determine when an initial condition subject to chaotic stirring will decay to zero and when it will give rise to a nonzero final state. Comparisons with full PDE simulations show that the reduced pulse model accurately predicts the threshold amplitude for a pulse initial condition to give rise to a nontrivial final steady state, and that the reduced plateau model gives an accurate picture of the dynamics of the system at large Damkoehler number. Published in Physica D (2006)

Second-order elliptic PDE with discontinuous boundary data

We shall consider the weak formulation of a linear elliptic model problem with discontinuous Dirichlet boundary conditions. Since such problems are typically not well-defined in the standard H^1-H^1 setting, we will introduce a suitable saddle point formulation in terms of weighted Sobolev spaces. Furthermore, we will discuss the numerical solution of such problems. Specifically, we employ an hp-discontinuous Galerkin method and derive an L^2-norm a posteriori error estimate. Numerical experiments demonstrate the effectiveness of the proposed error indicator in both the h- and hp-version setting. Indeed, in the latter case exponential convergence of the error is attained as the mesh is adaptively refined.

S.P.O.T.: Sensações, paixões, ódios e taras - a vida em palco: Relatório de estágio em assistência de encenação do espectáculo

Este estágio permitiu-me reflectir sobre questões fundamentais para a minha formação em Dramaturgia e Encenação. A capacidade de trabalho e coordenação requeridas a um encenador tomaram-se preocupações concretas no meu trabalho. Ter a noção de todos os elementos a ter em conta para criar um espectáculo permitiu-me compreender a importância individual de cada um, bem como a minúcia da harmonização entre eles. Esta viagem começa na origem e compreensão do texto, passando pela análise do trabalho do encenador, e culminando na observação da evolução do meu trabalho. Executar o que até agora apenas conhecia das linhas escritas por Peter Brook, Artaud, Stanislavki, António Damásio e Erving Goffman, entre outros, significa levantar um véu e ver com os meus olhos as texturas que compõem a arte do Teatro. ABSTRACT: This training period opened the field for broader reflection on fundamental issues related to Dramatology and Staging Techniques. The skills acquired, the coordination, and the endurance demanded from a stage director showed the actual dimension of the whole that one must consider when creating a show. namely. by understanding the importance of each and every individual on stage as well as the difficult minute details necessary to develop a sense of harmony with different parts. My voyage starts with the work, ending with the criticism of my own work. With practical staging experience - unveiling the most significant textures in the art of Theatre - I fully realized the writing of authors such as Brook. Artaud. Stanislavski, Damacio and Goffman.

Dramaturgia do aqui e agora: presença, recepção e sentido no corpo do ator

The actor is an actor during all the phases of creation and development of his character. (S) He goes beyond the moment of interpreting. In this sense, in her (his) daily life, the actor may use her (his) potential to extract from reality the necessary elements for the work of creation. This is a theoretical research which focus on the concept of presence in the actor s work, stretching the concept beyond the scene, encompassing different components such as the body, the word, the silence, the technique and the acting as the actor s stance in regards to his own reality. The objective of such stance is to integrate him (her) self in the environment, balancing his (hers) inner life with the outside life flow. To reach this objective, the research drew theoretical resources from the concept of presence in the actor s work according to BROOK, BARBA, GROTOWSKI and MNOUCHKINE and the studies on reception theory in ISER, 1996; GUMBRECHT, 2010. Thus, the dialogue between reader and actor high lights both as receivers in this work. A practical description of a street theater Kamchàtka show, featured by the Kamchàtka Company is used as an example of the research on the presence. The elements localized in this show are: play, listening, word, silence, meaning, relationship with here and now and the effects of the said presence

Reconstructing the last interglacial at Summit, Greenland: Insights from GISP2

The Eemian (last interglacial, 130-115 ka) was likely the warmest of all interglacials of the last 800 ka, with summer Arctic temperatures 3-5 degrees C above present. Here, we present improved Eemian climate records from central Greenland, reconstructed from the base of the Greenland Ice Sheet Project 2 (GISP2) ice core. Our record comes from clean, stratigraphically disturbed, and isotopically warm ice from 2,750 to 3,040 m depth. The age of this ice is constrained by measuring CH_4 and delta O^18 of O_2, and comparing with the historical record of these properties from the North Greenland Ice Core Project (NGRIP) and North Greenland Eemian Ice Drilling (NEEM) ice cores. The d^18 O_ice, d^15N of N_2, and total air content for samples dating discontinuously from 128 to 115 ka indicate a warming of similar to 6 degrees C between 127-121 ka, and a similar elevation history between GISP2 and NEEM. The reconstructed climate and elevation histories are compared with an ensemble of coupled climate-ice-sheet model simulations of the Greenland ice sheet. Those most consistent with the reconstructed temperatures indicate that the Greenland ice sheet contributed 5.1 m (4.1-6.2 m, 95% credible interval) to global eustatic sea level toward the end of the Eemian. Greenland likely did not contribute to anomalously high sea levels at ~127 ka, or to a rapid jump in sea level at ~120 ka. However, several unexplained discrepancies remain between the inferred and simulated histories of temperature and accumulation rate at GISP2 and NEEM, as well as between the climatic reconstructions themselves.

Eulerian-Lagrangian definition of coarse bed-load transport: Theory and verification with low-cost inertial measurement units

Fluvial sediment transport is controlled by hydraulics, sediment properties and arrangement, and flow history across a range of time scales. This physical complexity has led to ambiguous definition of the reference frame (Lagrangian or Eulerian) in which sediment transport is analysed. A general Eulerian-Lagrangian approach accounts for inertial characteristics of particles in a Lagrangian (particle fixed) frame, and for the hydrodynamics in an independent Eulerian frame. The necessary Eulerian-Lagrangian transformations are simplified under the assumption of an ideal Inertial Measurement Unit (IMU), rigidly attached at the centre of the mass of a sediment particle. Real, commercially available IMU sensors can provide high frequency data on accelerations and angular velocities (hence forces and energy) experienced by grains during entrainment and motion, if adequately customized. IMUs are subjected to significant error accu- mulation but they can be used for statistical parametrisation of an Eulerian-Lagrangian model, for coarse sediment particles and over the temporal scale of individual entrainment events. In this thesis an Eulerian-Lagrangian model is introduced and evaluated experimentally. Absolute inertial accelerations were recorded at a 4 Hz frequency from a spherical instrumented particle (111 mm diameter and 2383 kg/m3 density) in a series of entrainment threshold experiments on a fixed idealised bed. The grain-top inertial acceleration entrainment threshold was approximated at 44 and 51 mg for slopes 0.026 and 0.037 respectively. The saddle inertial acceleration entrainment threshold was at 32 and 25 mg for slopes 0.044 and 0.057 respectively. For the evaluation of the complete Eulerian-Lagrangian model two prototype sensors are presented: an idealised (spherical) with a diameter of 90 mm and an ellipsoidal with axes 100, 70 and 30 mm. Both are instrumented with a complete IMU, capable of sampling 3D inertial accelerations and 3D angular velocities at 50 Hz. After signal analysis, the results can be used to parametrize sediment movement but they do not contain positional information. The two sensors (spherical and ellipsoidal) were tested in a series of entrainment experiments, similar to the evaluation of the 111 mm prototype, for a slope of 0.02. The spherical sensor entrained at discharges of 24.8 ± 1.8 l/s while the same threshold for the ellipsoidal sensor was 45.2 ± 2.2 l/s. Kinetic energy calculations were used to quantify the particle-bed energy exchange under fluvial (discharge at 30 l/s) and non-fluvial conditions. All the experiments suggest that the effect of the inertial characteristics of coarse sediments on their motion is comparable to the effect hydrodynamic forces. The coupling of IMU sensors with advanced telemetric systems can lead to the tracking of Lagrangian particle trajectories, at a frequency and accuracy that will permit the testing of diffusion/dispersion models across the range of particle diameters.

Perfil logístico de Volkswagen desde la producción

Este análisis muestra detalladamente la línea de producción de la planta de Volkswagen, ubicada en México en el estado de Puebla. Se describe la capacidad operativa utilizada para satisfacer la demanda de la planta de producción de automóviles más grande de Latinoamérica, siendo clave para mantenerse en el mercado con estándares de calidad altos y contribuir al desarrollo de la economía del país. Asimismo, a nivel regional, esta planta se abastece de proveedores estratégicos ubicados en una zona cercana, ayudando a disminuir costos de transporte de piezas y tiempos de respuesta. Inicialmente se realiza una breve descripción del entorno económico de la empresa a nivel regional y del sector a nivel global para hacer énfasis en lo competitivo que es el mercado de la producción de automóviles. Posteriormente se describe la finalidad que tiene esta misión empresarial soportada por la Universidad del Rosario, donde se afianzan conocimientos importantes sobre un mercado de talla mundial. El siguiente aspecto es un diagnóstico de la empresa, donde se dan a conocer las marcas que hacen parte del grupo Volkswagen y la situación financiera que refleja la marca desde el 2012, revelando los ingresos obtenidos durante el período 2012-2014, gastos operacionales y factores que no se destacan positivamente como un flujo de caja negativo para el 2014. Posteriormente se plasman los conceptos teóricos necesarios para que el lector comprenda las variables inmersas en una planta de producción, destacando la teoría de colas y el diseño del layout de la empresa. Finalmente, se da una descripción detallada del proceso de producción en esta planta, donde se muestra la línea de producción, el ensamble y la importancia de un sistema operativo interno que depende principalmente de una alta inversión de tecnología e ingeniería que permite obtener un mayor beneficio en cada etapa del proceso.

Análisis de la influencia del programa de mejoramiento integral de barrios de Bogotá en el territorio del API El tesoro de la localidad de Ciudad Bolívar

La expansión urbana mediante asentamientos de origen informal ha ido aumentado en los últimos años debido al déficit en la oferta de vivienda formal, el costo del suelo urbano y factores económicos, sociales y culturales. Estos asentamientos no cuentan con infraestructura básica y los terrenos que generalmente son invadidos se encuentran en zonas de riesgo y no ofrecen las condiciones físicas y habitacionales adecuadas para el habitar de las personas. El distrito a través del Programa de Mejoramiento Integral de Barrios (PMIB) busca intervenir sobre los aspectos críticos en cada barrio, habilitar la infraestructura básica que permita su integración a la ciudad y mejorar la calidad de vida de los habitantes. Este proceso parte de delimitar las zonas críticas y definir las intervenciones físicas, sociales y ambientales que deben ser llevadas a cabo por diferentes entidades distritales. En este estudio se hace un análisis de las intervenciones que se han llevado a cabo en la Área Prioritaria de Intervención (API) El Tesoro, para analizar cuales intervenciones llevadas a cabo han sido exitosas y cuales requieren de ajustes para lograr un mejor impacto. Se encontró que estas intervenciones no han sido suficientes para mejorar las condiciones habitacionales de las personas, razón por lo cual es necesario revisar la política y formas de intervención.

Descripción de la prevalencia del boarding en la fundación santa fe de bogotá.

Introducción: El boarding es el fenómeno que ocurre cuando existen pacientes hospitalizados en urgencias sin una cama de hospitalización a la cual trasladarse, en la literatura mundial se ha identificado como un factor que repercute en la calidad y seguridad de la atención en urgencias. Este trabajo busca describir la prevalencia de dicho fenómeno en el servicio de urgencias de la Fundación Santa fe de Bogotá Metodología: Estudio observacional de prevalencia. Se incluyeron pacientes del mes de octubre de 2015 atendidos por especialistas en medicina de emergencias de la Fundación Santa fe de Bogotá. Se tomaron datos del turno realizado (mañana, tarde y noche), y datos del servicio de urgencias para su descripción. Resultados: La mediana de ocupación por boarding en urgencias fue del 68% con un rango intercuartil de 54-75%; en términos de tiempo en minutos, la mediana fue de 1054 minutos, con un rango intercuartil de 621-1490. Existen diferencias numéricas del tiempo en minutos de acuerdo el turno (mañana: 992,77 DE 519, tarde:1584,13 DE 1000,27 noche:1304,13 DE 2126,43). Discusión: El tiempo de boarding reportado para urgencias de la Fundación Santa fe de Bogotá es comparativamente mayor al descrito en la literatura mundial, se deben explorar en estudios analíticos posteriores los factores o variables que se asocien a la presencia de este fenómeno.