Clasificación de variables y reconciliación de datos en ingeniería de procesos

Las medidas de proceso de las plantas térmicas se utilizan para tareas de control, evaluación de rendimientos, optimización de la operación, etc. Frecuentemente se dispone de más medidas que las necesarias. La reconciliación consiste en ajustar las medidas redundantes de modo que obedezcan las leyes de conservación y cualquier otra restricción que incorpore el modelo matemático de la planta. Como resultado: (i) se detectan y eliminan los errores sistemáticos de medida; (ii) se obtiene un conjunto consistente de medidas ajustadas; (iii) se estiman las variables no medidas por el método de máxima verosimilitud y (iv) se obtienen intervalos de confianza para los resultados. En este trabajo se propone el método de la descomposición QR para analizar, descomponer y resolver los problemas de reconciliación lineal. Los problemas de reconciliación no lineal pueden resolverse iterativamente linealizando las ecuaciones del modelo matemático. Se presenta un ejemplo para ilustrar la aplicación de los procedimientos de cálculo propuestos.Peer Reviewe

Branching Deregulation and Merger Optimality

The U.S. banking industry has been characterized by intense merger activity in the absence of economies of scale and scope. We claim that the loosening of geographic constraints on U.S. banks is responsible for this consolidation process, irrespective of value-maximizing motives. We demonstrate this by putting forward a theoretical model of banking competition and studying banks’ strategic responses to geographic deregulation. We show that even in the absence of economies of scale and scope, bank mergers represent an optimal response. Also, we show that the consolidation process is characterized by merger waves and that some equilibrium mergers are not profitable per se -they yield losses- but become profitable as the waves of mergers unfold.Banking Competition, Deregulation, Mergers

Whom to Merge with? A Tale of the Spanish Banking Deregulation Process

We put forward a simple spatial competition model to study banks’ strategic responses to the Spanish asymmetric geographic deregulation. We find that once geographic deregulation process finishes, inter-regional mergers between the savings banks are optimal. We claim that the public good nature of the merging activities together with the incentives provided by the deregulation process are the driving factors behind the equilibrium merger of the savings banks. It seems that the economic crisis will finally force regional politicians to allow inter-regional caja mergers, letting the consequences of the removal of geographic barriers in the 80’s come to a fruition with a delay of thirty years.Banking Competition, Deregulation, Mergers

Bottomonium spectroscopy with mixing of eta_b states and a light CP-odd Higgs

The mass of the eta_b(1S), measured recently by BABAR, is significantly lower than expected from QCD predictions for the Upsilon(1S) - eta_b(1S) hyperfine splitting. We suggest that the observed eta_b(1S) mass is shifted downwards due to a mixing with a CP-odd Higgs scalar A with a mass m_A in the range 9.4 - 10.5 GeV compatible with LEP, CLEO and BABAR constraints. We determine the resulting predictions for the spectrum of the eta_b(nS) - A system and the branching ratios into tau^+ tau^- as functions of m_A.Comment: 4 pages, 4 figures, submitted to PRL, misprint correcte

Optimal operation and marginal costs in simple trigeneration systems including thermal energy storage

The development of high-efficiency energy systems is a pressing issue nowadays, motivated by economic, environmental, and social aspects. Trigeneration systems allow for the rational use of energy by means of appropriate energy integration and provide greater operational flexibility, which is particularly interesting for buildings, often characterized by variable electricity, heating, and cooling demands. The benefits of trigeneration systems can be enhanced by the incorporation of thermal energy storage (TES), which decouples production and consumption. This paper analyses the operation of a simple trigeneration system including TES. The optimal operation is obtained by a linear programming model that minimizes the total variable cost. A thermoeconomic analysis based on marginal cost assessment of the internal flows and final products of the system is carried out, allowing to explain the optimal operation of the system and the role of the TES in achieving the optimal solution. The analysis unravels the marginal cost formation process, presenting a clear route from the final products obtained to the resources consumed. This information can aid the design of new plants, the retrofit of existing ones, and the operational management to achieve the minimum operational cost

Optimal design of trigeneration systems for buildings considering cooperative game theory for allocating production cost to energy services

In the design of trigeneration plants for buildings, two fundamental issues must be addressed: the synthesis of the plant configuration (installed technologies and capacity, etc.) and the operational planning. Given the variety of technology options available and great diurnal and annual fluctuations in energy demands, finding the optimal supply system of energy services is a complex task. Cost allocation in multi-product systems requires special attention because the way in which allocation is made will affect the prices of the final products and, consequently, the consumers' behaviour. When a polygeneration plant is designed to serve different products, it is possible to achieve a lower total cost. However, if potential consumers are free to participate, the system's management should ensure that every participant shares the benefit of joint production. In trigeneration systems this implies that all consumers should achieve, at least, a lower cost for their demanded energy services than operating separately. The present work proposes a Mixed Integer Linear Programming model to determine the optimal configuration of trigeneration systems that must cover the energy demands of electricity, heating and cooling of a residential complex located in Zaragoza, Spain. The model considers the possibility of using a set of proposed alternative technologies within a superstructure and considers the optimal operation throughout a typical meteorological year. The objective function to be minimized is the total annual cost. The results indicate that compared to consumers standing alone, the optimal trigeneration system can achieve 10.6% cost saving. Ten different cost assessment methods to the three final energy products of the analyzed trigeneration system are rigorously compared. Cooperative game theory shows that all consumers benefit. Using the Shapley values as the distribution criterion, the savings for electricity, heating and cooling consumers are 4.8%, 20.9% and 11.1%, respectively