485 research outputs found
Particle size and potential toxic element speciation in municipal solid waste incineration (Mswi) bottom ash
The speciation of potentially toxic elements (PTE) in bottom ashes from municipal solid waste incineration (MSWI) and their relationship with grain size is investigated. The proposed enrichment of several potential toxic elements in lower sized grains is discussed, comparing the literature and new data on Parma’s waste incinerator. Results from X-ray fluorescence spectrometry (XRF), SEM-EDS, and XRD analyses on different grain size show (1) a positive Si-trend, correlated with grain size and few lithophile elements, such as Zr and Rb. In Parma, Al, K, Mg, and Fe also correlate with Si for the portion below 2 mm; (2) a Ca-trend, with a strong negative correlation with Si and a positive correlation with loss on ignition (LOI), S, Cl, Ti, Zn, Pb, and Sn. Mineralogical composition shows a little change in grain size, as in previous investigations, but with substantial differences in amorphous content. SEM-EDS analysis shows that the amorphous portion is highly heterogeneous, with portions coming from melting during incineration, residual glass, and unburnt loss on ignition (LOI). The above results show that PTE elements are either present as metals (such as Cu and Ni, or Zn, Pb and Sn) in carbonate, sulfate, and amorphous residual LOI portions
Introduzione soft alla matematica per l'economia e la finanza: I SISTEMI LINEARI
Quaderni di didattica. Dipartimento di Matematica Applicata. Università Ca'Foscari di Venezia
An evolutionary approach to preference disaggregation in a MURAME-based credit scoring problem
In this paper we use an evolutionary approach in order to infer the values of the parameters (weights of criteria, preference, indifference and veto thresholds) for developing
the multicriteria method MURAME. According to the logic of preference disaggregation, the problem consists in finding the parameters that minimize the inconsistency between
the model obtained with those parameters and that one connected with a given reference set of decisions revealed by the decision maker; in particular, two kinds of functions are
considered in this analysis, representing a measure of the model inconsistency compared to the actual preferential system. In order to find a numerical solution of the mathematical
programming problem involved, we adopt an evolutionary algorithm based on the Particle Swarm Optimization (PSO) method, which is an iterative heuristics grounded on swarm
intelligence. The proposed approach is finally applied to a creditworthiness evaluation problem in order to test the methodology on a real data set provided by an Italian bank
An MCDA-based approach for creditworthiness assessment
Il working paper è inserito nell'archivio RePEc.
http://ideas.repec.org/p/vnm/wpaper/177.htm
Introduzione soft alla matematica per l'economia e la finanza: il concetto di funzione come elemento base della modellizzazione
Quaderni di didattica. Dipartimento di Matematica Applicata. Università Ca'Foscari di Venezia
A fuzzy-based scoring rule for author ranking
The measurement of the quality of research has reached nowadays an increasing interest not only for scientific reasons but also for the critical problem of researchers' ranking, due to the lack of grant assignments. The most commonly used approach is based on the so-called h-index, even if the current literature debated a lot about its pros and cons. This paper, after a brief review of the h-index and of alternative models, focuses on the characterization and the implementation of a modified scoring rule approach by means of a fuzzy inference system a là Sugeno
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