Misurazione della performance nell'ottica del miglioramento continuo

Scopo del presente lavoro di tesi – dal titolo “Misurazione delle performance nell’ottica del miglioramento continuo. Il caso La Fortezza S.p.A.” – è lo sviluppo di un sistema di misurazione della performance aziendale in grado di supportare il management nel comprendere le dinamiche della formazione del valore della propria azienda e nello stabilire i piani di miglioramento continuo più idonei in ragione delle criticità specifiche del business. A tal fine viene costruito un sistema di indicatori di prestazione che ripercorrono i flussi di materia ed informazione in un’ottica di processo attraverso le funzioni aziendali e si forniscono due strumenti di analisi: − “Albero delle cause di ritardo” che evidenzia le responsabilità interne e/o esterne all’azienda che possono aver determinato consegne ritardate; − “Analisi delle interdipendenze” che esamina il tipo di relazione esistente tra gli indicatori consentendo di prevedere come eventuali interventi di miglioramento di una performance si ripercuotono sulle prestazione rilevate dalle altre misurazioni e di tutta l’azienda nel suo complesso

Insights into the relation between noise and biological complexity

Understanding under which conditions the increase of systems complexity is evolutionary advantageous, and how this trend is related to the modulation of the intrinsic noise, are fascinating issues of utmost importance for synthetic and systems biology. To get insights into these matters, we analyzed chemical reaction networks with different topologies and degrees of complexity, interacting or not with the environment. We showed that the global level of fluctuations at the steady state, as measured by the sum of the Fano factors of the number of molecules of all species, is directly related to the topology of the network. For systems with zero deficiency, this sum is constant and equal to the rank of the network. For higher deficiencies, we observed an increase or decrease of the fluctuation levels according to the values of the reaction fluxes that link internal species, multiplied by the associated stoichiometry. We showed that the noise is reduced when the fluxes all flow towards the species of higher complexity, whereas it is amplified when the fluxes are directed towards lower complexity species.Comment: 5 pages, 3 figure

A Tutte polynomial for toric arrangements

We introduce a multiplicity Tutte polynomial M(x,y), with applications to zonotopes and toric arrangements. We prove that M(x,y) satisfies a deletion-restriction recurrence and has positive coefficients. The characteristic polynomial and the Poincare' polynomial of a toric arrangement are shown to be specializations of the associated polynomial M(x,y), likewise the corresponding polynomials for a hyperplane arrangement are specializations of the ordinary Tutte polynomial. Furthermore, M(1,y) is the Hilbert series of the related discrete Dahmen-Micchelli space, while M(x,1) computes the volume and the number of integral points of the associated zonotope.Comment: Final version, to appear on Transactions AMS. 28 pages, 4 picture

Stationary Kirchhoff problems involving a fractional elliptic operator and a critical nonlinearity

This paper deals with the existence and the asymptotic behavior of non-negative solutions for a class of stationary Kirchhoff problems driven by a fractional integro-differential operator $\mathcal L_K$ and involving a critical nonlinearity. The main feature, as well as the main difficulty, of the analysis is the fact that the Kirchhoff function $M$ can be zero at zero, that is the problem is degenerate. The adopted techniques are variational and the main theorems extend in several directions previous results recently appeared in the literature

On-line Joint Limit Avoidance for Torque Controlled Robots by Joint Space Parametrization

This paper proposes control laws ensuring the stabilization of a time-varying desired joint trajectory, as well as joint limit avoidance, in the case of fully-actuated manipulators. The key idea is to perform a parametrization of the feasible joint space in terms of exogenous states. It follows that the control of these states allows for joint limit avoidance. One of the main outcomes of this paper is that position terms in control laws are replaced by parametrized terms, where joint limits must be avoided. Stability and convergence of time-varying reference trajectories obtained with the proposed method are demonstrated to be in the sense of Lyapunov. The introduced control laws are verified by carrying out experiments on two degrees-of-freedom of the humanoid robot iCub.Comment: 8 pages, 4 figures. Submitted to the 2016 IEEE-RAS International Conference on Humanoid Robot