Search results for " Opera"

Understanding the separation of anion mixtures by TiO2 membranes: Numerical investigation and effect of alkaline treatment on physicochemical propert…

2019

Abstract Mechanisms governing the rejection of ions from multi-ionic solutions, and especially the selectivity between various anions are not fully understood at the present time. In this study, it is proposed, in a first part, to investigate the evolution of electric and dielectric exclusion mechanisms when anions are mixed in a solution. For this purpose, the volumetric membrane charge Xd and the dielectric constant of the solution confined within pores ep are numerically assessed from rejection curves with a classic transport model. This study highlights that the rejection of the various anions is differently governed by electric and dielectric mechanisms but their contribution to mixtur…

Special issue of Computers and Operations Research: GRASP with Path Relinking: Developments and applications

2013

On the Assessment of Fitness to Drive: Steering and Brake Operative Forces

2021

[EN] The Directive (EU) 2015/653 aimed at facilitating that the maximum force that any disabled driver could make on the vehicle's primary controls could be adjusted to their needs. The technical adjustment in the vehicle's design requires a measurement of the operational forces applied by the driver on the steering and brake controls, in order to determine its functional capacity during the execution of driving maneuvers. The objective of this paper is to define the steering and braking operative forces used for driving current market M1 motor vehicles for the ¿fitness to drive assessment of drivers with physical disabilities. A total of 200 trials were performed with 17 different vehicles…

Assessing the Performance of Interactive Multiobjective Optimization Methods

2021

Interactive methods are useful decision-making tools for multiobjective optimization problems, because they allow a decision-maker to provide her/his preference information iteratively in a comfortable way at the same time as (s)he learns about all different aspects of the problem. A wide variety of interactive methods is nowadays available, and they differ from each other in both technical aspects and type of preference information employed. Therefore, assessing the performance of interactive methods can help users to choose the most appropriate one for a given problem. This is a challenging task, which has been tackled from different perspectives in the published literature. We present a …

Scheduling projects with limited number of preemptions

2009

A recent paper (Ballestin F, Valls V, Quintanilla S. Preemption in resource-constrained project scheduling. European Journal of Operational Research 2008;189:1136-152) revealed the potential benefits of allowing one interruption when scheduling activities in a resource-constrained project. This paper further investigates the effect of interruption on project length in more general cases. To achieve this, a new model that covers most practical applications of discrete activity preemption is proposed and a metaheuristic algorithm for the problem is developed. Computational experiments on the standard j120 and j30 sets generated using ProGen study the difference in makespan between allowing m …

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…

A Realistic Model to Support Rescue Operations After an Earthquake via UAVs

2022

In this paper, we consider the problem of completely flying over an area just hit by an earthquake with a fleet of Unmanned Aerial Vehicles (UAVs) to opportunely direct rescue teams. The cooperation between UAVs ensures that the search for possible survivors can be faster and more effective than the solutions currently implemented by civil protection. To study this scenario, we introduce the Cover by Multitrips with Priorities (CMP) problem, which tries to keep into account all the main real-life issues connected to the flight and coordination of the UAVs. We conduct a theoretical study to estimate the best number of UAVs and additional batteries, to give indications to the organization tha…

Managing information security risks during new technology adoption

2012

Author's version of an article in the journal: Computers and Security. Also available from the publisher at: http://dx.doi.org/10.1016/j.cose.2012.09.001 In the present study, we draw on previous system dynamics research on operational transition and change of vulnerability to investigate the role of incident response capability in controlling the severity of incidents during the adoption of new technology. Toward this end, we build a system dynamics model using the Norwegian Oil and Gas Industry as the context. The Norwegian Oil and Gas Industry has started to adopt new information communication technology to connect its offshore platforms, onshore control centers, and suppliers. In oil co…

Fake news on Facebook and their impact on supply chain disruption during COVID-19

2022

AbstractSocial media (SM) fake news has become a serious concern especially during COVID-19. In this study, we develop a research model to investigate to what extent SM fake news contributes to supply chain disruption (SCD), and what are the different SM affordances that contribute to SM fake news. To test the derived hypotheses with survey data, we have applied partial least square based structural equation modelling (PLS-SEM) technique. Further, to identify how different configurations of SC resilience (SCR) capabilities reduce SCD, we have used fuzzy set qualitative comparative analysis (fsQCA). The results show that SM affordances lead to fake news, which increases consumer panic buying…

Introducing ARTMO's Machine-Learning Classification Algorithms Toolbox: Application to Plant-Type Detection in a Semi-Steppe Iranian Landscape.

2022

Accurate plant-type (PT) detection forms an important basis for sustainable land management maintaining biodiversity and ecosystem services. In this sense, Sentinel-2 satellite images of the Copernicus program offer spatial, spectral, temporal, and radiometric characteristics with great potential for mapping and monitoring PTs. In addition, the selection of a best-performing algorithm needs to be considered for obtaining PT classification as accurate as possible . To date, no freely downloadable toolbox exists that brings the diversity of the latest supervised machine-learning classification algorithms (MLCAs) together into a single intuitive user-friendly graphical user interface (GUI). To…