Search results for " Programming"

Time operators, innovations and approximations

2003

Abstract We present a new approach to the spectral analysis and prediction of such complex systems for which the time evolution is described by a semigroup of operators. This approach is based on an extended concept of time operator and can be interpreted as a shift representation of dynamical systems. The time operator method includes the multiresolution analysis of wavelets as a particular case but can also be applied for a substantially larger class of dynamical systems. Among the examples where shift representation have been explicitly derived are exact endomorphisms, the diffusion equation, generalized shifts associated with the Haar or Faber–Schauder basis and some classes of stochast…

A Study on Effect of Physical Activity through Listening to Music on The Everyday Stress and Resilience of The Preschoolers Participating in a Full-d…

2013

Carbon sequestration in French agricultural soils: A spatial economic evaluation

2021

International audience; Soil organic carbon sequestration measures entail costs to farmers with different individual characteristics and located in different areas. A cost‐effective analysis taking into account these heterogeneities is crucial for developing effective public policy aimed at increasing carbon sequestration. We undertake such an analysis focusing on three soil organic carbon sequestration measures: no‐till, extension of temporary grasslands, and hedgerows. Through an optimization model applied to France, our results show that only extension of temporary grasslands can store carbon at low cost, though their potential for carbon sequestration is also low. For an ambitious carbo…

Rank response functions in an online learning environment

2021

Abstract We estimate rank response functions after receiving rank-order feedback in an online learning platform. We find that the shapes of the rank response functions depend on the outcome measure under consideration. For our effort measure, i.e., whether learners continue to interact with the platform, we can reject a linear rank response function and find significant evidence of a U-shaped relationship. For our performance measure, i.e., correctly solved exercises, we find no clear pattern overall but suggestive evidence for a linearly decreasing rank response function for individuals in the lower half of the ability distribution, i.e., the lower the rank the lower the performance.

An upper echelons perspective on information technology business value

2017

This paper argues that information technology (IT) outcomes are more valuable to companies when their top management team (TMT) moves from flirting with IT to marriage. Previous research has demonstrated an association between top management support (TMS) and IT value. We extend the concept of TMS with the imbrication metaphor to define the construct of TMT-IT imbrication, which allows us to account for a tighter and continuous entwining of the TMT and IT to create IT value. Our definition of the TMT-IT imbrication construct embraces four dimensions: involvement, participation, attention, and use. In addition, with the support of upper echelons (UE) theory, we explore certain managerial tra…

A comparison of corporate social responsibility engagement in the OECD countries with categorical data

2015

This note presents a new method to compare the engagement level of the OECD countries with the corporate social responsibility (CSR) activities when achievements of their companies are described by CSR standards. We introduce the eigenvector procedure developed by Herrero and Villar (2013), applying the analysis of group performance with categorical data. We find that differences in CSR engagement across OECD countries are quite low in the top and the bottom of the eigenvector classification compared with those of the GRI index. However, there are important differences across countries placed in the middle rank of these two classifications.

Discrete frequency models for inventory management – an introduction

2001

Abstract The paper deals with the problem of devising a periodic replenishment policy when orders must be periodic, but only a given, discrete set of order frequencies can be used. The multi-item, instantaneous replenishment case with known demand is studied. In particular, staggering policies somehow arranging replenishments not to come at the same time instants are considered. The paper is composed of three parts: first, a taxonomy of several versions of the discrete frequency problem is proposed, according to different elements; in the second part, a general mixed integer programming model is proposed which is able to capture the peculiarities of the whole spectrum of this kind of proble…

Implantación de recursos didácticos digitales en asignaturas de Organización de Empresas

2013

El objetivo de este artículo es presentar el protocolo de implantación de diversas herramientas didácticas, así como el nivel de satisfacción de los estudiantes que las utilizan. Los resultados muestran, primero, que no es posible crear un único protocolo aplicable a todos los recursos, debido a las diferencias en los objetivos didácticos existentes. Segundo, la valoración que los estudiantes hacen de la utilización de los recursos es muy positiva, aunque existen algunas diferencias entre las distintas herramientas. Estos resultados permiten mejorar los recursos y adecuarlos al perfil de los estudiantes para que éstos puedan sacar el mayor provecho posible.

Optimising the efficiency of olive harvesting considering operator safety

2019

Mechanical-assisted harvesting of olives, which is carried out using hand-held harvesting units that detach the drupes through vibration supplied by electric motor or combustion engines, is a widespread method used in southern Italy. Such machines are able to harvest more than 80% of the overall quantity of olives available per tree in 5–10 min, but their performance is influenced by several factors related to the mechanical characteristics of the device and to the features of the trees. Here the problem of optimising harvesting efficiency whilst minimising the health risks to the operators is investigated, with the aim of demonstrating that it is possible to determine an optimum harvesting…

Energy management strategy to reduce pollutant emissions during the catalyst light-off of parallel hybrid vehicles

2020

Abstract The transportation sector is a major contributor to both air pollution and greenhouse gas emissions. Hybrid electric vehicles can reduce fuel consumption and CO2 emissions by optimizing the energy management of the powertrain. The purpose of this study is to examine the trade-off between regulated pollutant emissions and hybrid powertrain efficiency. The thermal dynamics of the three-way catalyst are taken into account in order to optimize the light-off. Experimental campaigns are conducted on a spark-ignition engine to introduce simplified models for emissions, exhaust gas temperature, catalyst heat transfers and efficiency. These models are used to determine the optimal distribut…