Energy Efficiency of Hybrid-Power HetNets: A Population-like Games Approach

In this paper, a distributed control scheme based on population games is proposed. The controller is in charge of dealing with the energy consumption problem in a Heterogeneous Cellular Network (HetNet) powered by hybrid energy sources (grid and renewable energy) while guaranteeing appropriate quality of service (QoS) level at the same time. Unlike the conventional approach in population games, it considers both atomicity and non-anonymity. Simulation results show that the proposed population-games approach reduces grid consumption by up to about 12% compared to the traditional best-signal level association policy.U.S. Air Force Office of Scientific Research FA9550-17-1-0259Ministerio de Cultura y Deporte DPI2016-76493-C3-3-RMinisterio de Economía y Empresa DPI2017-86918-

Toward the Development of a Global Financial Safety Net or a Segmentation of the Global Financial Architecture?

This article examines the prospects for the development of a comprehensive global financial safety net (GFSN). It discusses the optimal layout of the GFSN, comprising the International Monetary Fund, regional financing arrangements (RFAs), as well as bilateral or multilateral central bank swap arrangements, and the relationship between these. It then briefly reviews and appraises the current structure and functioning of these different layers of the GFSN and discusses the need and scope for strengthening cooperation between RFAs and the IMF. It argues that the GFSN is still very patchy and there is little reason to expect significant progress in better collaboration between RFAs and the IMF as long as the latter’s governance structure is not significantly revamped. Indeed, risks are that the GFSN will become even more fragmented with the further development of the European Stability Mechanism and the emergence of the BRICS Contingent Reserve Arrangement. To prevent a further fragmentation of the GFSN, substantial governance reform of the IMF is urgently needed

Characterizing Multiple Solutions to the Time - Energy Canonical Commutation Relation via Internal Symmetries

Internal symmetries can be used to classify multiple solutions to the time energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR posessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.Comment: Accepted for publication in Physical Review A, 10 page

El coeficiente de arrastre sobre la superficie del mar como función de las características del oleaje

An analysis of the performance of parameterizations for the drag coefficient CD over the ocean is presented. The results were obtained by considering detailed observations from the recent IntOA experiment in which a co-existence of wind sea and swell provides characteristic mixed sea conditions in a wide range of wind speeds. Recent research has advanced our understanding of air-sea fluxes, proposing new functional forms for the drag coefficient, as well as applying wavelength scaling and determining dimensionally consistent expressions for the drag coefficient. Nevertheless, a detailed analysis of the influence of wind sea parameters confirms the need to include the sea state dependence on parameterizing CD for mixed sea conditions. It is also shown that better results are obtained when aerodynamic roughness is considered as a function of wave age and wave steepness, or equivalently if CD is expressed as a function of a characteristic peak frequency defined through the wave momentum spectrum.Se presenta un análisis del desempeño de algunas parametrizaciones del coeficiente de arrastre CD sobre la superficie del mar. Los resultados se obtienen a partir de observaciones detalladas durante el experimento IntOA. En ese experimento la existencia simultánea de oleaje generado localmente y oleaje que proviene de tormentas lejanas, nos brinda características únicas del estado del mar con constituyentes mixtas de oleaje en una gama amplia de velocidades del viento. A través de investigaciones recientes se ha avanzado en el conocimiento de los flujos entre el océano y la atmósfera, al proponer nuevas formas funcionales del coeficiente de arrastre, así como al utilizar expresiones dimensionalmente consistentes que se basan en escalas asociadas a la longitud de onda de las olas. Los resultados de este trabajo confirman la necesidad de incluir la influencia del estado del mar en las parametrizaciones del coeficiente de arrastre, especialmente bajo condiciones mixtas de oleaje. También se demuestra que se obtienen mejores resultados cuando la escala de rugosidad aerodinámica se considera como una función de la edad de la ola y de la pendiente del oleaje local o de forma equivalente, cuando CD se expresa como función de una frecuencia característica asociada al pico espectral que se determina mediante el espectro del momento del oleaje

Determinación del Desbalance en Sistemas Rotor-cojinete a velocidad constante: Método de Identificación Algebraica

The development of a mathematical model for an on-line algebraic identifier is presented in this work. This model is used for determining the unbalance and its related angular position on vibrating rotor-dynamic systems of multiple degrees of freedom. The proposed identifier was obtained from the basis of a finite element mathematical model for rotating systems of multiple degrees of freedom. The model was developed under the consideration of four degrees of freedom beam-type element, where rotational inertia, gyroscopic moments, shearing strains and inner and outer damping effects were included. The on time behavior of proposed identifier was assessed for unbalance identification and its related angular position; the constant-speed unbalanced vibration response obtained from numerical simulation was used as input data

Preferences of Mexican anesthesiologists for vecuronium, rocuronium, or other neuromuscular blocking agents: a survey

BACKGROUND: Several neuromuscular blocking (NMB) agents are available for clinical use in anesthesia. The present study was performed in order to identify preferences and behaviors of anesthesiologists for using vecuronium, rocuronium or other NMB agents in their clinical practice. MATERIAL AND METHODS: The cross-sectional survey was applied at the Updated Course of the Colegio Mexicano de Anestesiología performed last year. Of 989, 282 (28.5%) surveys were returned. RESULTS: Most anesthesiologists were working at both public and private hospitals, performed anesthetic procedures for hospitalized and ambulatory patients, and anesthetized children as well as adults. Respondents did not consider mechanomyography as the gold standard method for neuromuscular monitoring. The T(25) was not recognized as a pharmacodynamic parameter that represents the clinical duration of the neuromuscular block. Most answered that vecuronium induces less histamine release than rocuronium, had never used any neuromuscular monitor, did not know the cost of vecuronium and rocuronium, and preferred rocuronium in multiple-sampling vials and vecuronium in either a vial for single or multiple sampling. Rocuronium was preferred for emergency surgery in patients with full stomach only. Almost all of anesthesiologists that conserve the unused drug did it without refrigeration and more than 30% conserve the unused drug in one syringe for further use. CONCLUSION: Vecuronium was preferred for most clinical situations, and the decision for this choice was not based on costs. Storage of unused drugs without refrigeration in a single syringe for purpose of future use in several patients represented a dangerous common practice

Reconstructing the parameter space of non-analytical cosmological fixed points

Dynamical system theory is a widely used technique in the analysis of cosmological models. Within this framework, the equations describing the dynamics of a model are recast in terms of dimensionless variables, which evolve according to a set of autonomous first-order differential equations. The fixed points of this autonomous set encode the asymptotic evolution of the model. Usually, these points can be written as analytical expressions for the variables in terms of the parameters of the model, which allows a complete characterization of the corresponding parameter space. However, a thoroughly analytical treatment is impossible in some cases. In this work, we give an example of a dark energy model, a scalar field coupled to a vector field in an anisotropic background, where not all the fixed points can be analytically found. Then, we put forward a general scheme that provides a numerical description of the parameter space. This allows us to find interesting accelerated attractors of the system with no analytical representation. This work may serve as a template for the numerical analysis of highly complicated dynamical systems.Comment: 13 pages, 13 figures, 1 table. Changes match the published versio

Differential Gene Expression from Midguts of Refractory and Susceptible Lines of the Mosquito, Aedes aegypti, Infected with Dengue-2 Virus

Suppressive subtractive hybridization was used to evaluate the differential expression of midgut genes of feral populations of Aedes aegypti (Diptera: Culicidae) from Colombia that are naturally refractory or susceptible to Dengue-2 virus infection. A total of 165 differentially expressed sequence tags (ESTs) were identified in the subtracted libraries. The analysis showed a higher number of differentially expressed genes in the susceptible Ae. aegypti individuals than the refractory mosquitoes. The functional annotation of ESTs revealed a broad response in the susceptible library that included immune molecules, metabolic molecules and transcription factors. In the refractory strain, there was the presence of a trypsin inhibitor gene, which could play a role in the infection. These results serve as a template for more detailed studies aiming to characterize the genetic components of refractoriness, which in turn can be used to devise new approaches to combat transmission of dengue fever

Binary Collisions and the Slingshot Effect

We derive the equations for the gravity assist manoeuvre in the general 2D case without the constraints of circular planetary orbits or widely different masses as assumed by Broucke, and obtain the slingshot conditions and maximum energy gain for arbitrary mass ratios of two colliding rigid bodies. Using the geometric view developed in an earlier paper by the authors the possible trajectories are computed for both attractive or repulsive interactions yielding a further insight on the slingshot mechanics and its parametrization. The general slingshot manoeuvre for arbitrary masses is explained as a particular case of the possible outcomes of attractive or repulsive binary collisions, and the correlation between asymptotic information and orbital parameters is obtained in general.Comment: 12 pages, 7 figures, accepted for publication Dec'07, Celestial Mechanics and Dynamical Astronom

Evolutionary-game-based dynamical tuning for multi-objective model predictive control

Model predictive control (MPC) is one of the most used optimization-based control strategies for large-scale systems, since this strategy allows to consider a large number of states and multi-objective cost functions in a straightforward way. One of the main issues in the design of multi-objective MPC controllers, which is the tuning of the weights associated to each objective in the cost function, is treated in this work. All the possible combinations of weights within the cost function affect the optimal result in a given Pareto front. Furthermore, when the system has time-varying parameters, e.g., periodic disturbances, the appropriate weight tuning might also vary over time. Moreover, taking into account the computational burden and the selected sampling time in the MPC controller design, the computation time to find a suitable tuning is limited. In this regard, the development of strategies to perform a dynamical tuning in function of the system conditions potentially improves the closed-loop performance. In order to adapt in a dynamical way the weights in the MPC multi-objective cost function, an evolutionary-game approach is proposed. This approach allows to vary the prioritization weights in the proper direction taking as a reference a desired region within the Pareto front. The proper direction for the prioritization is computed by only using the current system values, i.e., the current optimal control action and the measurement of the current states, which establish the system cost function over a certain point in the Pareto front. Finally, some simulations of a multi-objective MPC for a real multi-variable case study show a comparison between the system performance obtained with static and dynamical tuning.Peer ReviewedPostprint (author's final draft