Search results for " operations"
showing 10 items of 1066 documents
Adapting RRI public engagement indicators to the Spanish scientific and innovation context: a participatory methodology based on AHP and content anal…
2022
The paradigm proposed by Responsible Research and Innovation in the European Commission policy discourse identifies Public Engagement as a key area for exchange and dialogue among multiple actors following an inclusive and participatory process. Two definite set of indicators have already arisen at European level to monitor Public Engagement activities in the Science and Innovation realm. Our study aims to propose a deliberative participatory process, which involves selected stakeholders, for the adaptation of the European indicators to the specific Spanish scientific and innovation context. The methodological procedure is of exploratory nature and will be based in a combination of, on the …
A Branch-and-Cut method for the Capacitated Location-Routing Problem
2011
International audience; Recent researches in the design of logistic networks have shown that the overall distribution cost may be excessive if routing decisions are ignored when locating depots. The Location-Routing Problem (LRP) overcomes this drawback by simultaneously tackling location and routing decisions. The aim of this paper is to propose an exact approach based on a Branch-and-Cut algorithm for solving the LRP with capacity constraints on depots and vehicles. The proposed method is based on a zero-one linear model strengthened by new families of valid inequalities. The computational evaluation on three sets of instances (34 instances in total), with 5–10 potential depots and 20–88 …
Swing options in commodity markets: a multidimensional Lévy diffusion model
2013
Author's version of an article in the journal: Mathematical Methods of Operations Research. Also available from the publisher at: http://dx.doi.org/10.1007/s00186-013-0452-7 We study valuation of swing options on commodity markets when the commodity prices are driven by multiple factors. The factors are modeled as diffusion processes driven by a multidimensional Lévy process. We set up a valuation model in terms of a dynamic programming problem where the option can be exercised continuously in time. Here, the number of swing rights is given by a total volume constraint. We analyze some general properties of the model and study the solution by analyzing the associated HJB-equation. Furthermo…
A computational study of LP-based heuristic algorithms for two-dimensional guillotine cutting stock problems
2002
In this paper we develop and compare several heuristic methods for solving the general two-dimensional cutting stock problem. We follow the Gilmore-Gomory column generation scheme in which at each iteration a new cutting pattern is obtained as the solution of a subproblem on one stock sheet. For solving this subproblem, in addition to classical dynamic programming, we have developed three heuristic procedures of increasing complexity, based on GRASP and Tabu Search techniques, producing solutions differing in quality and in time requirements. In order to obtain integer solutions from the fractional solutions of the Gilmore-Gomory process, we compare three rounding procedures, rounding up, t…
Comprensión de textos expositivos académicos en e-book Reader y en papel: influencia del conocimiento previo de dominio y la aptitud verbal
2018
espanolResumen: En un estudio del que participaron 102 estudiantes universitarios, se comparo la comprension en la lectura de textos expositivos academicos impresos versus en formato de e-book Reader. Se examinaron los efectos del soporte, del conocimiento especifico de dominio previo del lector y la aptitud verbal. Asimismo se indagaron las actitudes de los estudiantes hacia los soportes textuales antes y despues de la experiencia. Los resultados sugieren que el e-book Reader beneficiaria a los lectores competentes, y/o que podria promover mayor actividad metacognitiva en los procesos de comprension. Asimismo, las opiniones hacia el e-book Reader cambiaron despues de la experiencia, aunque…
EMISSION FACTORS, VEHICLE MODAL ACTIVITY AND ROAD OPERATIONS. A MESOSCOPIC APPROACH
2009
Current studies underline that vehicle emissions are highly linked to modal vehicle activity and a modal approach to traffic-related air quality modeling is suitable to estimate mobile source contribution to air quality. Pollutant emissions depend on characteristics of vehicles in traffic flow and on road operating conditions predictable after the implementation of the road project; then, the usual emission rate models do not predict properly the on-road vehicles emissions of modal traffic events, such as those ones occurring at intersections. Moreover modal activity analysis carried out at micro scale level, as required by modal emission models, will be still necessary to value reliable em…
HABILIDADES MATEMÁTICAS INICIALES Y DIFICULTADES MATEMÁTICAS PERSISTENTES
2017
Abstract.INITIAL MATH SKILLS AND PERSISTENT MATH DIFFICULTIESThe aim of the present study was to analyse the differences in certain basic mathematical competences (for example, counting, logical operations, magnitude comparability skills) assessed in. Early Childhood Education between children with persistent difficulties in the area of mathematics in 2nd Primary Education and children with adequate performance. The final sample of the study consisted of 180 children (composed initially of 209 pre-schoolers), of which 6.6% showed persistent mathematics difficulties (n = 12) and 45.5% presented an adequate performance in both measurements (n = 82). In Early Childhood Education we administere…
Reflections on the Hohmann Transfer
2004
Walter Hohmann was a civil engineer who studied orbital maneuvers in his spare time. In 1925, he published an important book (Ref. 1) containing his main result, namely, that the most economical transfer from a circular orbit to another circular orbit is achieved via an elliptical trajectory bitangent to the terminal orbits. With the advent of the space program some three decades later, the Hohmann transfer maneuver became the most fundamental maneuver in space. In this work, we present a complete study of the Hohmann transfer maneuver. After revisiting its known properties, we present a number of supplementary properties which are essential to the qualitative understanding of the maneuver.…
Is ICT the Key to Development?
2010
Using panel data for 52 developed and developing countries over the period 1998-2006, this article examines the links between information and communication technology diffusion and human development. We conducted a panel regression analysis of the investments per capita in healthcare, education and information and communication technology against human development index scores. Using a quantile regression approach, our findings suggest that changes in healthcare, education and information and communication technology provision have a stronger impact on human development index scores for less developed than for highly developed countries. Furthermore, at lower levels of development education…
The curvilinear effect of manufacturing outsourcing and captive-offshoring on firms' innovation: The role of temporal endurance
2019
Abstract This paper aims to contribute to the open debate in the literature on the effect of global sourcing strategies on firm performance by studying the consequences of manufacturing outsourcing and captive-offshoring for the innovation capability of the firm. We grounded our hypotheses based on the outsourcing and offshoring literature and by narrowing our focus to the effects of persisting in their adoption over time. We tested our hypotheses using data from a sample of 368 manufacturing companies listed on NASDAQ stock market. The paper provides theoretical explanations and empirical findings for the inverted U-shaped influence of keeping doing captive-offshoring on new product develo…