A Weakly Pareto Compliant Quality Indicator

In multi-objective optimization problems, the optimization target is to obtain a set of non-dominated solutions. Comparing solution sets is crucial in evaluating the performances of different optimization algorithms. The use of performance indicators is common in comparing those sets and, subsequently, optimization algorithms. A good solution set must be close to the Pareto-optimal front, well-distributed, maximally extended and fully filled. Therefore, an effective performance indicator must encompass these features as a whole and must be Pareto dominance compliant. Unfortunately, some of the known indicators often fail to properly reflect the quality of a solution set or cost a lot to compute. This paper demonstrates that the Degree of Approximation (DOA) quality indicator, is a weakly Pareto compliant unary indicator that gives a good estimation of the match between the approximated front and the Pareto-optimal front. Moreover, DOA computation is easy and fast

Tiltrotor with double mobile wing

A convertiplane structure (100), having a longitudinal axis x and a plane n orthogonal to it, comprises a main wing (120) arranged to rotate about at least one transversal rotation axis y, an auxiliary wing (130), which is located back with respect to main wing (120), and arranged to rotate about at least one transversal rotation axis y', at least two main propellers (220) located on the main wing (120), and at least two auxiliary propellers (230) located on the auxiliary wing (130). The auxiliary wing (130) is located at a vertical height higher than main wing (120). Two vertical wings (140) are also provided located in such a way that the projections on the plane n of the main wing (120), of the auxiliary wing (130) and of the vertical wings (140) shape a closed polygon, thus reducing the induced drag and increasing the overall aerodynamic efficiency

Sensitivity analysis of agent-based models: a new protocol

Agent-based models (ABMs) are increasingly used in the management sciences. Though useful, ABMs are often critiqued: it is hard to discern why they produce the results they do and whether other assumptions would yield similar results. To help researchers address such critiques, we propose a systematic approach to conducting sensitivity analyses of ABMs. Our approach deals with a feature that can complicate sensitivity analyses: most ABMs include important non-parametric elements, while most sensitivity analysis methods are designed for parametric elements only. The approach moves from charting out the elements of an ABM through identifying the goal of the sensitivity analysis to specifying a method for the analysis. We focus on four common goals of sensitivity analysis: determining whether results are robust, which elements have the greatest impact on outcomes, how elements interact to shape outcomes, and which direction outcomes move when elements change. For the first three goals, we suggest a combination of randomized finite change indices calculation through a factorial design. For direction of change, we propose a modification of individual conditional expectation (ICE) plots to account for the stochastic nature of the ABM response. We illustrate our approach using the Garbage Can Model, a classic ABM that examines how organizations make decisions

Sensitivity analysis of agent-based models: a new protocol

Agent-based models (ABMs) are increasingly used in the management sciences. Though useful, ABMs are often critiqued: it is hard to discern why they produce the results they do and whether other assumptions would yield similar results. To help researchers address such critiques, we propose a systematic approach to conducting sensitivity analyses of ABMs. Our approach deals with a feature that can complicate sensitivity analyses: most ABMs include important non-parametric elements, while most sensitivity analysis methods are designed for parametric elements only. The approach moves from charting out the elements of an ABM through identifying the goal of the sensitivity analysis to specifying a method for the analysis. We focus on four common goals of sensitivity analysis: determining whether results are robust, which elements have the greatest impact on outcomes, how elements interact to shape outcomes, and which direction outcomes move when elements change. For the first three goals, we suggest a combination of randomized finite change indices calculation through a factorial design. For direction of change, we propose a modification of individual conditional expectation (ICE) plots to account for the stochastic nature of the ABM response. We illustrate our approach using the Garbage Can Model, a classic ABM that examines how organizations make decisions

How does peer-to-business lending affect financial policy of SMEs?

We study how alternative sources of financing, Peer to Business (P2B) platforms, affect the financial policy of small and medium-sized enterprises (SMEs). We find that firms obtaining P2B loans are higher quality firms as they are large, more profitable, with higher sales growth, higher bank debt, and lower default rates. We conclude that P2B platforms are serving the same type of firms than traditional banks. While P2B loans do not seem to affect investment policy and performance, it does affect financial policy. Firms use the availability of P2B to reduce long-term bank debt, while they increase short-term bank debt following P2B lending. In addition, SMEs increase the number of lending relationships and reduce their dependence on a single bank, in particular those with less stable funding and lower liquidity. Our findings suggest that FinTech lending complements the debt financing choices of SMEs and allows them to diversify away from traditional banks.publishersversionpublishe

Flight dynamics model for preliminary design of PrandtlPlane wing configuration with sizing of the control surfaces

The purpose of this paper is to present design procedures and tools for the aerodynamic optimization of a large freighter aircraft with a PrandtlPlane configuration. Suitable optimization tools have been developed and are shortly described in the paper; sensitivity analyses for high speed flight conditions have been performed, and, also, low speed performances are evaluated to provide a complete preliminary design of the PrandtlPlane freighter

Aerodynamic optimization of a large PrandtlPlane configuration

The purpose of this paper is to present design procedures and tools for the aerodynamic optimization of a large freighter aircraft with a PrandtlPlane configuration. Suitable optimization tools have been developed and are shortly described in the paper; sensitivity analyses for high speed flight conditions have been performed, and, also, low speed performances are evaluated to provide a complete preliminary design of the PrandtlPlane freighter

Health Pedagogy and Narrative-based Strategies to Promote Healthy Eating Behaviours and Prevent Obesity in Schoolchildren: an Experimental Protocol Designed in Salento

Overweight and obesity in paediatric population are becoming serious public health problems, reaching epidemic proportions in the world and being recognized as the "new pandemic of the twenty first century". Food choices and nutritional habits are strictly linked to the cultural dimension of communities and symbolic representations of food. Even in Italy, young generations are moving away from the culture of Mediterranean Diet (MD) – recognized as Intangible Heritage of Humanity by UNESCO – being at risk of losing both their identity and the health benefits associated with MD. In this frame, health pedagogy (i.e. nutritional education) can play a fundamental role in promoting the adoption of healthy eating behaviours since childhood, addressing at the same time such crucial binomials as food-health and environment-sustainability. In the last decades, a huge variety of school-based obesity prevention programs have been introduced. Among those, according to scientific evidence, narrative-based strategies may be helpful in promoting healthy nutritional habits among schoolchildren. Actually, narration is a useful tool in didactic practice, impacting on the emotional and motivational dimension of learning, thus represent-ing a valuable vehicle of health contents. On these bases, as DREAM Laboratory of Health Pedagogy, we have proposed to the Department of Prevention of the Local Health Authority ASL Lecce – specifically involving the Food Hygiene and Nutrition Service (SIAN) – to implement a research protocol aimed at assessing if narrative-based strategies could be more effective than other educational approaches in promoting the adoption of healthy eating behaviours among schoolchildren