Search results for "Tesi"
showing 10 items of 686 documents
An Analysis of the Influence of Noneffective Instructions in Linear Genetic Programming
2020
Abstract Linear Genetic Programming (LGP) represents programs as sequences of instructions and has a Directed Acyclic Graph (DAG) dataflow. The results of instructions are stored in registers that can be used as arguments by other instructions. Instructions that are disconnected from the main part of the program are called noneffective instructions, or structural introns. They also appear in other DAG-based GP approaches like Cartesian Genetic Programming (CGP). This article studies four hypotheses on the role of structural introns: noneffective instructions (1) serve as evolutionary memory, where evolved information is stored and later used in search, (2) preserve population diversity, (3)…
Stochastic analysis of dynamical systems with delayed control forces
2006
Abstract Reduction of structural vibration in actively controlled dynamical system is usually performed by means of convenient control forces dependent of the dynamic response. In this paper the existent studies will be extended to dynamical systems subjected to non-normal delta-correlated random process with delayed control forces. Taylor series expansion of the control forces has been introduced and the statistics of the dynamical response have been obtained by means of the extended Ito differential rule. Numerical application provided shows the capabilities of the proposed method to analyze stochastic dynamic systems with delayed actions under delta-correlated process contrasting statist…
On coincidence of feedback and global Stackelberg equilibria in a class of differential games
2021
This paper shows for a class of differential games that the global Stackelberg equilibrium (GSE) coincides with the feedback Stackelberg equilibrium (FSE), although the GSE assumes that the leader/regulator an- nounces at the initial time the regulatory instrument rule she will follow for the rest of the game, while in the FSE, the regulator at any time chooses the optimal level of the regulatory instrument rate. This coincidence is based on the fact that the FSE is calculated using dynamic programming what implies that although the regulator chooses the regulatory instrument rate level that maximizes social welfare, the first-order condition for the maximization of the right-hand side of t…
On the advantages of combining differential algorithms and log-polar vision for detection of self-motion from a mobile robot
2001
Abstract This paper describes the design and implementation on programmable hardware (FPGAs) of an algorithm for the detection of self-mobile objects as seen from a mobile robot. In this context, ‘self-mobile’ refers to those objects that change in the image plane due to their own movement, and not to the movement of the camera on board of the mobile robot. The method consists on adapting the original algorithm from Chen and Nandhakumar [A simple scheme for motion boundary detection, in: Proceedings of the IEEE International Conference on Systems, Man and Cybernetics, 1994] by using foveal images obtained with a special camera whose optical axis points towards the direction of advance. It i…
Strict quasi-concavity and the differential barrier property of gauges in linear programming
2014
Concave gauge functions were introduced to give an analytical representation of cones. In particular, they give a simple and a practical representation of the positive orthant. There is a wide choice of concave gauge functions with interesting properties, representing the same cone. Besides the fact that a concave gauge cannot be identically zero on a cone(), it may be continuous, differentiable and even on its interior. The purpose of the present paper is to present another approach to penalizing the positivity constraints of a linear programme using an arbitrary strictly quasi-concave gauge representation. Throughout the paper, we generalize the concept of the central path and the analyti…
Development of Point-to-Point Path Control in Actuator Space for Hydraulic Knuckle Boom Crane
2020
This paper presents a novel method for point-to-point path control for a hydraulic knuckle boom crane. The developed path control algorithm differs from previous solutions by operating in the actuator space instead of the joint space or Cartesian space of the crane. By operating in actuator space, almost all the parameters and constraints of the system become either linear or constant, which greatly reduces the complexity of both the control algorithm and path generator. For a given starting point and endpoint, the motion for each actuator is minimized compared to other methods. This ensures that any change in direction of motion is avoided, thereby greatly minimizing fatigue, jerky motion,…
Sublimazione e repressione: la crisi delle scienze europee e la musica barocca
2009
Dopo la Controriforma continua l'espansione e la sublimazione dell'eros, tipica del Rinascimento: fino al 1683 circa; quindi predomina la repressione dell'eros e lo sfruttamento delle energie vitali per la produzione industriale. Alla fluidità sonora della musica rinascimentale e barocca subentra improvvisamente la rigidezza sonora della musica dell'illuminismo e del rococò.
Deficiencias epistemológicas en la enseñanza habitual de los conceptos de campo y potencial eléctrico
1997
This article intends to analyse up to what extent the scarce learning produced when introducing the basic concepts on electrostatics is due to deficiencies and inadequacies in its routine teaching. So, on the one hand, we analyse what have been the principal epistemological leaps forward in the making of electricity as a science. On the other hand, we analyse Physics books and the teachers’ opinions.
The tensor of interaction of a two-level system with an arbitrary strain field
2007
The interaction between two-level systems (TLS) and strain fields in a solid is contained in the diagonal matrix element of the interaction hamiltonian, $\delta$, which, in general, has the expression $\delta=2[\gamma]:[S]$, with the tensor $[\gamma]$ describing the TLS ``deformability'' and $[S]$ being the symmetric strain tensor. We construct $[\gamma]$ on very general grounds, by associating to the TLS two objects: a direction, $\hat\bt$, and a forth rank tensor of coupling constants, $[[R]]$. Based on the method of construction and on the invariance of the expression of $\delta$ with respect to the symmetry transformation of the solid, we conclude that $[[R]]$ has the same structure as …
Experiences of using the ISBAR tool after an intervention: A focus group study among critical care nurses and anaesthesiologists.
2021
Objective The ISBAR tool is a structured approach to communication between healthcare professionals and refers to Identity, Situation, Background, Assessment, and Recommendation. The objective of this study was to explore how critical care nurses and anaesthesiologists experience using the ISBAR tool in clinical practice. Design Three focus groups were conducted with a total of three anaesthesiologists and 14 critical care nurses from two hospitals in Norway after they had attended an intervention. Setting The intervention consisted of two days at a university, with a four-month interval between, attending resource lectures and simulation exercises focusing on the ISBAR tool. The focus grou…