Non-centralized Control for Flow-based Distribution Networks: A Game-theoretical Insight

This paper solves a data-driven control problem for a flow-based distribution network with two objectives: a resource allocation and a fair distribution of costs. These objectives represent both cooperation and competition directions. It is proposed a solution that combines either a centralized or distributed cooperative game approach using the Shapley value to determine a proper partitioning of the system and a fair communication cost distribution. On the other hand, a decentralized noncooperative game approach computing the Nash equilibrium is used to achieve the control objective of the resource allocation under a non-complete information topology. Furthermore, an invariant-set property is presented and the closed-loop system stability is analyzed for the non cooperative game approach. Another contribution regarding the cooperative game approach is an alternative way to compute the Shapley value for the proposed specific characteristic function. Unlike the classical cooperative-games approach, which has a limited application due to the combinatorial explosion issues, the alternative method allows calculating the Shapley value in polynomial time and hence can be applied to large-scale problems.Generalitat de Catalunya FI 2014Ministerio de Ciencia y Educación DPI2016-76493-C3-3-RMinisterio de Ciencia y Educación DPI2008-05818Proyecto europeo FP7-ICT DYMASO

Aplicación del modelo modergis en el uso sostenible en la dendroenergía y los biocombustibles para países en vía de desarrollo- caso Colombia.

Numerosos países en vía de desarrollo caso Colombia, contienen un enorme potencial de recursos en energías renovables como la dendroenergía incluidos los biocombustibles, pero no se utilizan en gran magnitud ni se han incorporado al Mix Energético Nacional debido a la falta de herramientas que las evalué e integre de manera armónico y con criterio sostenible. En tal sentido la Universidad Nacional de Colombia y el Centro de Investigaciones Energéticas Medioambientales y Tecnológicas - CIEMAT de España, han desarrollado conjuntamente una herramienta de planificación energética sostenible denominada - MODERGIS - que tiene como objeto la incorporación, evaluación y análisis de energías renovables con énfasis a la dendroenergía y los biocombustibles utilizando las técnicas de los Sistemas de Información Geográfica - SIG, como instrumento alternativo de planificación y uso sostenible ambiental, social, económico y cultural del uso del suelo. El modelo esta conformado por tres componentes: ENERDEM modelo de demanda- oferta de energía, ENERSIG: espacialización e integración de energías renovables mediante los Sistemas de Información Geográfica - SIG y ENERSOS modelo basado en métodos de análisis multiobjetivo tendientes a optimizar las dimensiones de la sostenibilidad de las fuentes energética, incorporando el análisis de ciclo de vida. Los resultados preliminares del modelo presentan 6.8 Millones de hectáreas factibles en el uso de la Dendroenergía, el cual significaría un potencial de 4400 MW instalables si se dedicara en la producción de energía eléctrica. En biocombustibles el Biodiesel de palma de aceite arroja un potencial de 1017 millones de barriles y 54 millones de barriles de etanol de caña de azúcar, el cual justificaría proporciones de abastecimiento interno con las mezclas de E10 y B5, quedando un gran potencial para interferir el mercado internacional, lo cual con la metodología de ModerGIS tiene incluido los criterios de sostenibilidad que son necesarios para ingresar a estos mercados.An essential element to reach sustainable development is an appropriate and reliable energy supply. This helps to eradicate poverty, improve human welfare, and to raise quality of life in the population. However, many regions in the world do not have a reliable supply, and its use exceeds economic limits, creating a dichotomy between growth and sustainability. World institutons such as United Nations and its organization UNESCO, have demonstrated that current energy production and consumption models are not sustainable in a medium term. Many countries, especially those that are in development such as Colombia, have a great potential of renewable energy resources that have not been used or incorporated into the energy mix due to the lack of tools to evaluate and to integrate them with a sustainability criteria. Then, “Universidad Nacional de Colombia” (Colombia) and “Centro de Investigaciones Energéticas Medioambientales y Tecnológicas – CIEMAT” (Spain) have jointly developed an integrated energy planning tool named MODERGIS. Its objective is to incorporate, evaluate and analyze renewable resources such as wood energy including biofuels. This model comprises three constitutive elements: an energy supply-demand model (ENERDEM), an integration and space definition of renewable energy through geographic information systems (ENERSIG), and a multi-objectiveanalysis to optimize sustainability dimensions of energy sources (ENERSOS). The current paper shows some of the preliminary results of this model, and discusses on the methodological issues faced during its development. Further and more expanded results are expected to be published in the near future

A case of atypical disseminated herpes simplex virus 1 with hepatitis in a liver transplant recipient: the need for dermatologic evaluation

Disseminated herpes simplex virus (HSV) is mainly seen in immunocompromised individuals. Atypical lesions can be present in both primary infection and reactivation disease. Compared with the general population, inmunocompromised hosts are at greater risk of increased persistency and severity of clinical manifestations, including severe systemic involvement such as esophagitis, meningitis, and hepatitis. Herein, we report the case of a liver transplant recipient with atypical disseminated herpes simplex virus-1 complicated by HSV-related hepatitis. Dermatological consultation and histological assessment were crucial for a correct diagnosis and treatment

A review of electrical metering accuracy standards in the context of dynamic power quality conditions of the grid

Numerous changes in electrical grid schemes, like the inclusion of renewable energy, the rise of non-linear loads and the emergence of electric vehicle charging, increases variable power quality conditions of the grid. In this dynamic scenario where energy could flow in both directions and the waveforms could be highly distorted, accuracy becomes a crucial factor for the correct measurement of electrical energy and power values. Errors in the assessment of these values have significant ramifications for revenue, billing and/or control. This non-ideal power quality scenario produces an error in electricity meters, that is not yet well known since there is no standardised procedure to calibrate meters under typical or emerging distorted waveform conditions. Current standards relevant for revenue energy meters like EN 50470-3:2006 allows measurements error up to ±2.5% while local regulations could be even more permissive. In order to establish an electricity fair trade market and meet expectations from consumers and utilities, electricity meters should arguably comply with higher accuracy standards. In this paper, the pertinence and possible impact of including tests under distorted waveform conditions, as well as new accuracy requirements on standards applicable to electricity meters for billing purposes will be discussed

Challenges for smart electricity meters due to dynamic power quality conditions of the grid : a review

During the last few years, Smart Electricity Meters have been deployed in several countries all around the world, replacing the trustable Electromechanical meter and even other electronic meters. Since the early deployments, many concerns and complaints from customers which do not trust Smart Meters accuracy have appeared. As a result, researchers of different institutions have been testing electricity meters under distorted waveform conditions and proposing methods to calibrate such meters in a more representative real world operative conditions. Applicable accuracy standards and regulations indicate a maximum distortion factor of 3% of the sinusoidal waveform for voltage and current during the calibration, which is not representative of many modern dynamic power quality scenarios. New tests and recommendations have been issued by regulatory bodies, but they are still not mandatory for meters to be certified. With many changes upcoming in the near future for the electrical Smart Grid like the inclusion of renewables, increasing non-linear loads, electric charging vehicles and other emerging technologies, the power quality conditions of the grid is expected to be significantly affected. In this paper, a review of the current and upcoming challenges for the smart meters is presented

Liquidity constraints in free post-secondary education: Evidence from Colombia

This paper provides evidence of the importance of liquidity constraints in a tuition-free post-secondary education setting in Colombia. We exploit exogenous variation in the relative cost of tuition-free vocational education from a nationwide cash transfer program. We show that eligibility for a USD 136 grant every other month increases enrollment by up to 12 percentage points. We also show that men with larger returns to education are more affected by the availability of grants, which is consistent with the presence of liquidity constraints. However, we do not find the same for women. This paper highlights the importance of non-tuition costs and discusses whether individuals under-invest in their human capital when free education is available

Solución de sistemas de ecuaciones ralas en clusters de computadoras

En este artículo se presenta una estrategia de paralelización en clusters del método de Gauss-Seidel para la solución de sistemas de ecuaciones ralas. Desde el punto de vista de la solución numérica para matrices de coeficients con poca densidad de elemtnso no nulos, se siguen los lineamientos estándares. Es decir: esquemas de alamcenamiento especiales (Solamente se almacenan los elementos no nulos) y métodos iterativos de búsqueda de solución por aproximaciones sucesivas.\nDesde el punto de vista de la paralelización del procesamiento en clusters de computadoras, se siguen dos principios básicos: distribución de datos unidimensaional y utilización de mensajes broadcast para toda comunicación de datos entre procesos. La distribución de datos unidimensional facilita al máximo la distribución de carga de procesamiento aún en el caso de clusters heterogéneos (que sin embargo no se presentan en este artículo) La utilización de mensajes broadcast para toda comunicación de datos entre procesos está directamente orientada a la optimización de rendimiento de las comunicaciones en la mayoría de los clusters instalados y que se utilizan para cómputo paralelo La interconexión más usual de estos clusters es la provista por las redes Ethernet, y por lo tanto puede implementar los mensajes broadcast a nivel físico con sobrecarga mínima.\nSe presenta el análisis de rendimiento paralelo y además los resultados obtenidos en una red local de computadoras heterogéneas que se utilizan como si fueran homogéneas. En este caso se utiliza una implementación de la biblioteca MPI (Message Passage Interface) para la comunicación entre procesos.Eje: IV - Workshop de procesamiento distribuido y paralel

A Methodology to Engineer and Validate Dynamic Multi-level Multi-agent Based Simulations

This article proposes a methodology to model and simulate complex systems, based on IRM4MLS, a generic agent-based meta-model able to deal with multi-level systems. This methodology permits the engineering of dynamic multi-level agent-based models, to represent complex systems over several scales and domains of interest. Its goal is to simulate a phenomenon using dynamically the lightest representation to save computer resources without loss of information. This methodology is based on two mechanisms: (1) the activation or deactivation of agents representing different domain parts of the same phenomenon and (2) the aggregation or disaggregation of agents representing the same phenomenon at different scales.Comment: Presented at 3th International Workshop on Multi-Agent Based Simulation, Valencia, Spain, 5th June 201