Search results for " Program"

A model of internal and external competition in a High Speed Rail line

2015

This paper is a contribution to evaluate structural and behavioral changes in railway passenger markets. The novel elements of our analysis are the following: (i) the consideration of inter-modal and intra-modal competition, (ii) the presence of public and private operators, and (iii) endogenous service frequency. After calibrating the model using actual data from two Spanish High Speed Rail lines, simulation exercises allow us to conclude the following. Privatization, whether entry occurs or not, would prompt an increase in prices and a reduction in the number of train services, eventually leading to welfare decreases, as compared with a regime where the incumbent rail operator remained pu…

LE AREE INTERNE PER LO SVILUPPO DEL TERRITORIO E LA COMPLEMENTARITÀ DI PROGRAMMI E STRUMENTI FRA LE POLITICHE EUROPEE DI SVILUPPO RURALE E DI COESIONE

Le Aree Interne rappresentano un tema particolarmente importante per la programmazione e la spesa dei fondi comunitari nel periodo 2014-2020 perché costituiscono il più grande esempio di complementarità fra le Politiche europee di sviluppo rurale e di coesione. Per lo sviluppo di queste Aree è stata creata una Strategia Nazionale per le Aree Interne (SNAI) che mira alla valorizzazione ed al recupero di tutti quei territori (rurali, montuosi, svantaggiati) dal carattere marginale rispetto alla disponibilità e all’offerta di servizi essenziali. La peculiarità di tale Strategia è quella di promuovere lo sviluppo di aree che sono uniformemente distribuite in tutto il comprensorio nazionale a di…

Determining a Random Schrödinger Operator : Both Potential and Source are Random

2020

We study an inverse scattering problem associated with a Schr\"odinger system where both the potential and source terms are random and unknown. The well-posedness of the forward scattering problem is first established in a proper sense. We then derive two unique recovery results in determining the rough strengths of the random source and the random potential, by using the corresponding far-field data. The first recovery result shows that a single realization of the passive scattering measurements uniquely recovers the rough strength of the random source. The second one shows that, by a single realization of the backscattering data, the rough strength of the random potential can be recovered…

Reverse inheritance in statically typed object-oriented programming languages

2010

Reverse inheritance is a new class reuse mechanism, an experimental implementation of which we have built for Eiffel. It enables a more natural design approach, factorization of common features (members), insertion of classes into an existing hierarchy etc. Due to its reuse potential in Eiffel we consider exploring its capabilities in other industrial-strength programming languages like C++, Java and C#.

A grid representation for distributed virtual environments

2004

Fast Internet connections and the widespread use of high performance graphic cards are making Distributed Virtual Environments (DVE) very common nowadays. The architecture and behavior of these systems are very similar to new grid computing applications where concepts such as sharing and high scalability are extremely exploited. However, there are several key issues in these systems that should still be improved in order to design a scalable and cost-effective DVE system. One of these key issues is the partitioning problem. This problem consists of efficiently assigning clients (3-D avatars) to the arbiters (servers) in the system. As an alternative to the ad-hoc heuristic proposed in the l…

Exploring parallel capabilities of an innovative numerical method for recovering image velocity vectors field

2010

In this paper an efficient method devoted to estimate the velocity vectors field is investigated. The method is based on a quasi-interpolant operator and involves a large amount of computation. The operations characterizing the computational scheme are ideal for parallel processing because they are local, regular and repetitive. Therefore, the spatial parallelism of the process is studied to rapidly proceed in the computation on distributed multiprocessor systems. The process has shown to be synchronous, with good task balancing and requiring a small amount of data transfer.

Uniqueness of solutions for some elliptic equations with a quadratic gradient term

2008

We study a comparison principle and uniqueness of positive solutions for the homogeneous Dirichlet boundary value problem associated to quasi-linear elliptic equations with lower order terms. A model example is given by −Δu + λ |∇u| 2 u r = f (x) ,λ , r >0. The main feature of these equations consists in having a quadratic gradient term in which singularities are allowed. The arguments employed here also work to deal with equations having lack of ellipticity or some dependence on u in the right hand side. Furthermore, they could be applied to obtain uniqueness results for nonlinear equations having the p-Laplacian operator as the principal part. Our results improve those already known, even…

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)…

Equivalence closure in the two-variable guarded fragment

2015

We consider the satisfiability and finite satisfiability problems for the extension of the two-variable guarded fragment in which an equivalence closure operator can be applied to two distinguished binary predicates. We show that the satisfiability and finite satisfiability problems for this logic are 2-ExpTime-complete. This contrasts with an earlier result that the corresponding problems for the full two-variable logic with equivalence closures of two binary predicates are 2-NExpTime-complete.

A study of LoRaWAN protocol performance for IoT applications in smart agriculture

2020

Abstract The use of Internet of Things (IoT) is becoming increasingly common in agribusiness to increase food production capacity for the expanding global population. Recently, low-power wide-area networks (LPWANs) have been used in the development of IoT applications that require low power consumption and low data transmission rates. LoRaWAN is considered the most suitable communication network for LPWANs for IoT applications in smart agriculture. In this paper, we present an in-depth study of the performance of the LoRaWAN communication network in the context of an IoT application for a pilot farm. We consider several scenarios and analyze simulation results by using Network Simulator 3. …