Search results for " optimization."
showing 10 items of 2333 documents
Dynamic reconfiguration systems for PV plant: Technical and economic analysis
2020
Solar plants suffer of partial shading and mismatch problems. Without considering the generation of hot spots and the resulting security issues, a monitoring system for the health of a PV plant should be useful to drive a dynamic reconfiguration system (DRS) to solve bottlenecks due to different panels’ shading. Over the years different DRS architectures have been proposed, but no suggestions about costs and benefits have been provided. Starting from technical subjects such as differences of the topologies driving the hardware complexity and number of components, this paper identifies the cost of DRS and its lifetime, and based on these issues it provides an economic analysis for a 6 kWp PV…
An Environmental Analysis of the Effect of Energy Saving, Production and Recovery Measures on Water Supply Systems under Scarcity Conditions
2015
Water is one of the primary resources provided for maintaining quality of life and social status in urban areas. As potable water is considered to be a primary need, water service has usually been managed without examining the economic and environmental sustainability of supply processes. Currently, due to increases in energy costs and the growth of environment preservation policies, reducing water leakage, energy consumption and greenhouse gas (GHG) production have become primary objectives in reducing the environmental footprint of water service. The present paper suggests the implementation of some performance indicators that show the interdependence of water loss, energy consumption and…
A Simple Operating Strategy of Small-Scale Battery Energy Storages for Energy Arbitrage under Dynamic Pricing Tariffs
2015
Price arbitrage involves taking advantage of an electricity price difference, storing electricity during low-prices times, and selling it back to the grid during high-prices periods. This strategy can be exploited by customers in presence of dynamic pricing schemes, such as hourly electricity prices, where the customer electricity cost may vary at any hour of day, and power consumption can be managed in a more flexible and economical manner, taking advantage of the price differential. Instead of modifying their energy consumption, customers can install storage systems to reduce their electricity bill, shifting the energy consumption from on-peak to off-peak hours. This paper develops a deta…
Symmetry breaking in a constrained cheeger type isoperimetric inequality
2015
We study the optimal constant in a Sobolev inequality for BV functions with zero mean value and vanishing outside a bounded open set. We are interested in finding the best possible embedding constant in terms of the measure of the domain alone. We set up an optimal shape problem and we completely characterize the behavior of optimal domains.
Discretization estimates for an elliptic control problem
1998
An optimal control problem governed by an elliptic equation written in variational form in an abstract functional framework is considered. The control is subject to restrictions. The optimality conditions are established and the Ritz-Galerkin discretization is introduced. If the error estimate corresponding to the elliptic equation is given as a function like where h is the discretization parameter and is an integer, then the error estimates for the optimal control, for the optimal state and for the optimal value are obtained. These results are applied first for a Two-Point BVP and next for a 2D/3D elliptic problem as state equation. Next a spectral method is used in the discretization proc…
A linearization technique and error estimates for distributed parameter identification in quasilinear problems
1996
The identification problem of a nonlinear functional coefficient in elliptic and parabolic quasilinear equations is considered. A distributed observation of the solution of the corresponding equation is assumed to be known a priori. An identification method is introduced, which needs only a linear equation to be solved in each iteration step of the optimization. Estimates of the rate of convergence for the proposed approach are proved, when the equation is discretized with the finite element method with respect to space variables. Some numerical results are given.
A dynamic life-cycle model for the provisioning of software testing services
2014
Information and communications technology (ICT)-enabled international sourcing of software-intensive systems and services (eSourcing) is a powerful strategy for managing businesses more effectively. China is becoming a superpower for eSourcing service provisioning, but most Chinese providers are small- or medium-sized and leverage the mediated eSourcing model, delivering services to foreign ICT clients who interface with end-clients onshore. This model restricts the providers to low-value projects. This paper probes eSourcing of software testing services within the Chinese market because testing is one of the best ICT services small- and medium-sized providers can provide to develop domain …
On Boundary Conditions for Wedge Operators on Radial Sets
2008
We present a theorem about calculation of fixed point index for k-$\psi$-contractive operators with 0 < k <1 defined on a radial set of a wedge of an infinite dimensional Banach space. Then results on the existence of eigenvectors and nonzero fixed points are obtained.
Analysis of the Combustion Process in a Hydrogen-Fueled CFR Engine
2023
Green hydrogen, produced using renewable energy, is nowadays one of the most promising alternatives to fossil fuels for reducing pollutant emissions and in turn global warming. In particular, the use of hydrogen as fuel for internal combustion engines has been widely analyzed over the past few years. In this paper, the authors show the results of some experimental tests performed on a hydrogen-fueled CFR (Cooperative Fuel Research) engine, with particular reference to the combustion. Both the air/fuel (A/F) ratio and the engine compression ratio (CR) were varied in order to evaluate the influence of the two parameters on the combustion process. The combustion duration was divided in two par…
Methodologies for the Exploitation of Existing Energy Corridors. GIS Analysis and DTR Applications
2018
The exploitation of power lines currently in operation has now become a common practice among electric system operators. The construction of new power lines requires taking economic, political and social problems into consideration. This paper considers two methodologies adopted by the Italian Transmission System Operator (TSO), Terna S.p.A.: Dynamic Thermal Rating (DTR) and Laser Imaging Detection and Ranging-Geographic Information System (L-GIS). DTR systems dynamically calculate the real transport capacity of a power line. The L-GIS system allows, after the geo-referencing of the power line, the management of any interference between the line and the nearby obstacles, permitting the opti…