Search results for " programmi"
showing 10 items of 1629 documents
Characteristics of neuronal systems in the visual cortex
1987
The coupling complexity of cortical areas makes it very difficult to analyse them experimentally. Studies of model systems provide the possibility of adapting the analysis to the available data base and elaborating the fundamental properties that depend on the structure of the system. We propose a model system of variable complexity that is spatially two-dimensional and time-dependent, uses feedback for iteration and smoothing, includes the mapping of the cortical networks and can be nonlinear as the case requires. Combining such elementary systems on the basis of neuroanatomical findings enables us to simulate cortical mappings and to interpret neurophysiological data. The decisive factor …
Identifying Pathways to Computer Science : The Long-Term Impact of Short-Term Game Programming Outreach Interventions
2019
Short-term outreach interventions are conducted to raise young students’ awareness of the computer science (CS) field. Typically, these interventions are targeted at K–12 students, attempting to encourage them to study CS in higher education. This study is based on a series of extra-curricular outreach events that introduced students to the discipline of computing, nurturing creative computational thinking through problem solving and game programming. To assess the long-term impact of this campaign, the participants were contacted and interviewed two to five years after they had attended an outreach event. We studied how participating in the outreach program affected the students’ perceptio…
Bootstrapping profit change: An application to Spanish banks
2012
The aim of this study is to provide a tool which enables us to conduct statistical analysis in the context of changes in productivity and profit. We build on previous initiatives to decompose profit change into mutually exclusive and exhaustive sources. To do this we use distance functions, which are calculated empirically using linear programming techniques. However, we may not learn a great deal by solving these linear programs unless methods of statistical analysis are used to examine the properties of the relevant estimators. Our purpose is to provide a methodology based on bootstrap that allows us to conduct statistical inference for the profit change decomposition. Thus, it will be po…
An Approach to the Automatic Comparison of Reference Point-Based Interactive Methods for Multiobjective Optimization
2021
Solving multiobjective optimization problems means finding the best balance among multiple conflicting objectives. This needs preference information from a decision maker who is a domain expert. In interactive methods, the decision maker takes part in an iterative process to learn about the interdependencies and can adjust the preferences. We address the need to compare different interactive multiobjective optimization methods, which is essential when selecting the most suited method for solving a particular problem. We concentrate on a class of interactive methods where a decision maker expresses preference information as reference points, i.e., desirable objective function values. Compari…
Model-based specification and validation of the dual-mode adaptive MAC protocol
2018
Wireless sensor and actuator networks (WSANs) rely on MAC protocols to coordinate access to the wireless medium access and for managing the radio unit on each device. The dual-mode adaptive MAC (DMAMAC) protocol is a recently proposed protocol designed to reduce the energy consumption of the radio communication in WSANs. The DMAMAC protocol targets the industrial WSANs used for real-time process control. At its core, DMAMAC exploits the distinction between transient and steady of the controlled plant process to dynamically adapt the MAC superframe structure and thereby conserve energy. The switch between steady and transient mode of operation is a safety-critical part of the protocol. The c…
Implementation of a web and mobile solution for vehicular management based on Aspects Architecture and Agile Methodologies: An educational approach f…
2017
espanolEn el presente articulo se detallan el analisis, aplicacion de metodologias agiles, y tecnologias de codigo abierto en el desarrollo de una aplicacion web y movil, para automatizar y controlar el parque automotor de la Universidad Tecnica Particular de Loja (UTPL), dicha aplicacion fue desarrollada por los profesionales en formacion del componente educativo Programacion Web en marco del proyecto Computacion Afectiva. Dentro de las funciones esenciales del aplicativo esta la gestion de vehiculos que implica el registro: ordenes de combustible y mantenimiento, facturas, proveedores, conductores y vehiculos; ademas de la gestion de prestamos de vehiculos que implica el registro de solic…
On the function of cell systems in area 18. Part I
1981
In addition to the asymmetry of the spatial coupling and of the specific temporal combination of excitation and inhibition, the non-linearity is very pronounced in area 18. Taking the sequence of a linear operation and a stationary nonlinear characteristic as a model, the experimental findings can be systematized and a cell classification specified which departs from the customary ones. The hypercomplex cell system probably originates in recurrent inhibition and leads to differentiation of the patterns along their contour line. Problems of cell classification and of the type of parallelism in the visual cortex are discussed.
Resolvent estimates for the magnetic Schrödinger operator in dimensions $$\ge 2$$
2019
It is well known that the resolvent of the free Schr\"odinger operator on weighted $L^2$ spaces has norm decaying like $\lambda^{-\frac{1}{2}}$ at energy $\lambda$. There are several works proving analogous high-frequency estimates for magnetic Schr\"odinger operators, with large long or short range potentials, in dimensions $n \geq 3$. We prove that the same estimates remain valid in all dimensions $n \geq 2$.
PT-symmetry and Schrödinger operators. The double well case
2015
We study a class of $PT$-symmetric semiclassical Schrodinger operators, which are perturbations of a selfadjoint one. Here, we treat the case where the unperturbed operator has a double-well potential. In the simple well case, two of the authors have proved in [6] that, when the potential is analytic, the eigenvalues stay real for a perturbation of size $O(1)$. We show here, in the double-well case, that the eigenvalues stay real only for exponentially small perturbations, then bifurcate into the complex domain when the perturbation increases and we get precise asymptotic expansions. The proof uses complex WKB-analysis, leading to a fairly explicit quantization condition.
Improving the Representativeness of a Simple Random Sample: An Optimization Model and Its Application to the Continuous Sample of Working Lives
2020
This paper proposes an optimization model for selecting a larger subsample that improves the representativeness of a simple random sample previously obtained from a population larger than the population of interest. The problem formulation involves convex mixed-integer nonlinear programming (convex MINLP) and is, therefore, NP-hard. However, the solution is found by maximizing the size of the subsample taken from a stratified random sample with proportional allocation and restricting it to a p-value large enough to achieve a good fit to the population of interest using Pearson&rsquo