Search results for "sensitivity analysi"

Economic assessment of sicilian loquat orchards

2015

The majority of Italian production of loquat (Eriobotrya japonica) derives from the Palermo province, along the northern Sicilian coast. However, this area is characterized by family orchards, traditional cultural techniques, and inadequate commercial organization. These appear to affect negatively the production costs and reduce the farmers’ income, decreasing the competitiveness of Sicilian loquat orchards. This study evaluates the economic viability of Sicilian loquat orchards by means of cost-benefit analysis (CBA). In particular, for the investment assessment some financial indicators have been calculated such as net present value (NPV), discounted payback time (DPBT), and internal r…

Economic assessment of Eucalyptus (spp.) for biomass production as alternative crop in Southern Italy

2015

The increase in energy prices and the stagnation of sales prices of the main agricultural commodities required a rethinking of farm production strategies. Since during the last years, thanks to a series of policies aimed at promoting renewable sources it has been a rapid diffusion of lignocellulosic biomass species, this paper aimed at evaluating the economic feasibility of the introduction of eucalyptus (Eucalyptus spp.) as energy crop for farmers of Southern Italy, by comparing it with traditional crop rotations. In particular, economic analysis has been carried out in a representative case study located in the Sicilian hilly hinterland where, in 2013, it has been built a biomass plant fo…

Projecting biodiversity and wood production in future forest landscapes: 15 key modeling considerations

2017

A variety of modeling approaches can be used to project the future development of forest systems, and help to assess the implications of different management alternatives for biodiversity and ecosystem services. This diversity of approaches does however present both an opportunity and an obstacle for those trying to decide which modeling technique to apply, and interpreting the management implications of model output. Furthermore, the breadth of issues relevant to addressing key questions related to forest ecology, conservation biology, silviculture, economics, requires insights stemming from a number of distinct scientific disciplines. As forest planners, conservation ecologists, ecologica…

Multi-parameter analysis of the obstacle scattering problem

2022

Abstract We consider the acoustic field scattered by a bounded impenetrable obstacle and we study its dependence upon a certain set of parameters. As usual, the problem is modeled by an exterior Dirichlet problem for the Helmholtz equation Δu + k 2 u = 0. We show that the solution u and its far field pattern u ∞ depend real analytically on the shape of the obstacle, the wave number k, and the Dirichlet datum. We also prove a similar result for the corresponding Dirichlet-to-Neumann map.

Modeling Political Corruption in Spain

2021

Political corruption is a universal phenomenon. Even though it is a cross-country reality, its level of intensity and the manner of its effect vary worldwide. In Spain, the demonstrated political corruption cases that have been echoed by the media in recent years for their economic, judicial and social significance are merely the tip of the iceberg as regards a problem hidden by many interested parties, plus the shortage of the means to fight against it. This study models and quantifies the population at risk of committing political corruption in Spain by identifying and quantifying the drivers that explain political corruption. Having quantified the problem, the model allows changes to be …

Implementation of sparse forward mode automatic differentiation with application to electromagnetic shape optimization

2011

In this paper, we present the details of a simple lightweight implementation of the so-called sparse forward mode automatic differentiation (AD) in the C++programming language. Our implementation and the well-known ADOL-C tool (which utilizes taping and compression techniques) are used to compute Jacobian matrices of two nonlinear systems of equations from the MINPACK-2 test problem collection. Timings of the computations are presented and discussed. Moreover, we perform the shape sensitivity analysis of a time-harmonic Maxwell equation solver using our implementation and the tapeless mode of ADOL-C, which implements the dense forward mode AD. It is shown that the use of the sparse forward …

Shape optimization utilizing consistent sensitivities

2010

Sensitivity Analysis in Nonrandomized Longitudinal Mediation Analysis

2021

Mediation analysis relies on an untestable assumption of the no omitted confounders, which posits that an omitted variable that confounds the relationships between the antecedent, mediator, and outcome variables cannot exist. One common model in alcohol addiction studies is a nonrandomized latent growth curve mediation model (LGCMM), where the antecedent variable is not randomized, the two covarying mediators are latent intercept and slope modeling longitudinal effect of the repeated measures mediator, and an outcome variable that measures alcohol use. An important gap in the literature is lack of sensitivity analysis techniques to assess the effect of the violation of the no omitted confou…

Optimization of trigeneration systems by Mathematical Programming: influence of plant scheme and boundary conditions

2014

The large potential for energy saving by cogeneration and trigeneration in the building sector is scarcely exploited due to a number of obstacles in making the investment attractive. The analyst often encounters difficulties in identifying optimal design and operation strategies, since a number of factors, either endogenous (i.e. related with the energy load profiles) and exogenous (i.e. related with external conditions like energy prices and support mechanisms), influence the economic viability. In this paper a decision tool is presented, that simultaneously optimizes the plant lay-out, the sizes of the main components and their operation strategy. For a specific building in the hotel sect…

Sensitivity Analysis and Frequency Dynamics of Grid-Connected Converters with Virtual Inertia

2021

For the participation in the frequency control of the system, power converters can be controlled with different strategies and methods, sharing the common concept of virtual inertia capability. In this work, a sensitivity analysis of two main categories of converter controls with virtual inertia is presented. The considered schemes are a grid-following current vector control with additional virtual inertia block and a grid-forming control scheme based on virtual synchronous machine concept. A proper basis for the comparison is first assessed providing an analytical correlation between the control parameters of the two schemes. For the two control strategies, the sensitivity analysis of the …