Search results for "Operations"
showing 10 items of 1692 documents
Byproduct production of minor metals: Threat or opportunity for the development of clean technologies? The PV sector as an illustration
2013
Abstract Today, the fight against global warming and the coming hydrocarbon exhaustion involve a drastic increase of clean energies. These technologies resort to many minor metals which are byproduct of major metals. We will take the definition of Hageluken and Mesker (2010, Complex Life Cycles of Precious and Special Metals. In: Edition Thomas E. Graedel, Ester van der Voet (Eds.), Strungmann Forum Report, Linkages of Sustainability, MIT Press) to show precisely what minor metals are: “[they are] metals that have relatively low production or usage, which occur in low ore concentrations, are regarded as rare, or are not traded at major public exchanges”. We will analyze the byproduct status…
Cluster emergence: combining pre-existing conditions and triggering factors
2016
AbstractThis article argues that the emergence of regional clusters relies on both necessary pre-existing conditions for cluster appearance in general and triggering factors that cause clusters to emerge in particular places. This approach is used to analyse two ‘critical cases’; the emergence of the synthetic-knowledge boat building industry in the Arendal area in Norway from the mid-1950s and the analytical-knowledge cancer medicine industry in Oslo around the year 2000. Although the industries and the contexts are otherwise very different, the framework turns out to be useful in interpreting the emergence of the two clusters. However, the specific pre-existing conditions and the triggeri…
Innovation Dynamics in Space: Local Actors and Local Factors
1997
This paper addresses the issue of technogenesis and its geographical pattern. It aims to offer both a general analysis framework and a test on innovation data from several European cities. This framework is mainly built on the product life-cycle and the incubation approach. On the basis of this framework, it is argued that the phases of an industrial life-cycle have several firm-specific effects. First, these phases influence innovativeness and thus profit levels, output and employment of firms in a spatially distinct way. Second, the phases of the life-cycle mirror the importance of local factors for innovations, and third, they affect strategic decisions of firms, inter alia by influencin…
Sharing economy and incumbents' pricing strategy: The impact of Airbnb on the hospitality industry
2019
Abstract In this paper, we examine how the emergence of sharing economy platforms influences incumbents' price responses. Grounding on the literature on price reactions to new entrants and on the unique characteristics of the sharing economy, we argue that the effect of the penetration of the sharing economy on incumbents' prices is not straightforward, and actually depends on the type of incumbents as well as certain product/service offer characteristics. Indeed, relying on a large sample of hotel price offerings from the Italian market, we find that the effect of the growing relevance of the sharing economy (exemplified by Airbnb) on incumbents' prices depends on the type of incumbents (l…
La filiera siciliana della pasta: un'applicazione della netchain analysis
2016
The system of Sicilian durum wheat is facing, as indeed is happening to the entire food system, the evolution of consumption patterns toward higher quality requirements: health-wise, primarily, but also including some intangible requirements. Recent acquisitions in the field of healthy food, have called attention to some specific characteristics of Sicilian durum wheat. The durum wheat sector represents a major landmark for regional agriculture, being by far the most widespread arable crop in Sicily; a crop that, over the past 30 years, has evolved considerably, due to the impact of EU regulations. Currently, the whole Sicilian cereal-pasta chain shows shortcomings in organization and size,…
Dynamic error-components models with autocorrelated disturbances : a brief survey
1997
Studying dynamic error component models with autocorrelated disturbances has started very recently in econometrics analysis of panel data. There is no article or book which tackles this topic exhaustively. In this study, a brief survey of these models is presented. The within, between, OLS, GLS, maximum likelihood and instrumental variable estimators are especially analysed, and the particular characteristics of these models are underlined each time.
Do commodity assets hedge uncertainties? What we learn from the recent turbulence period?
2022
AbstractThis study analyses the impact of different uncertainties on commodity markets to assess commodity markets' hedging or safe-haven properties. Using time-varying dynamic conditional correlation and wavelet-based Quantile-on-Quantile regression models, our findings show that, both before and during the COVID-19 crisis, soybeans and clean energy stocks offer strong safe-haven opportunities against cryptocurrency price uncertainty and geopolitical risks (GPR). Soybean markets weakly hedge cryptocurrency policy uncertainty, US economic policy uncertainty, and crude oil volatility. In addition, GSCI commodity and crude oil also offer a weak safe-haven property against cryptocurrency uncer…
Externalities and article citations: experience of a national public health journal (Gaceta Sanitaria)
2016
Purpose: The purpose of the study was to analyze the determinants of citations such as publication year, article type, article topic, article selected for a press release, number of articles previously published by the corresponding author, and publication language in a Spanish journal of public health. Methods: Observational study including all articles published in Gaceta Sanitaria during 2007-2011. We retrieved the number of citations from the ISI Web of Knowledge database in June 2013 and also information on other variables such as number of articles published by the corresponding author in the previous 5 years (searched through PubMed), selection for a press release, publication langua…
Comparing conventional and organic citrus grower efficiency in Spain
2014
This paper compares the organic and conventional citriculture systems in Spain from the perspective of their technical efficiency. The primary objective of the research is to compare the relative efficiency of these two systems in relation to a metafrontier that envelops both technologies. In addition, the article analyses how efficient each growing system is at using its own technology, that is, when farms’ efficiency is benchmarked in relation to the best practices in their group. Contrary to conventional practice, farms’ performance is analyzed in terms of specific growing tasks: soil and plant cover management, pruning, fertilization and phytosanitary treatments. The results obtained hi…
Autoencoders and Recurrent Neural Networks Based Algorithm for Prognosis of Bearing Life
2018
Bearings are one of the most critical components in electric motors, gearboxes and wind turbines. Therefore, bearing fault detection and prognosis of remaining useful life are important to prevent productivity losses. In this study, a novel method is proposed for prognosis of bearing life using an autoencoder and recurrent neural networks-based prediction algorithm. Promising results have been obtained from the experimental data. A monotonic upward trend of the produced health indicator is obtained for all test cases, being one of critical indicators of a proper prognosis. The remaining useful life estimation is moderately accurate under a limited data.