196,122 research outputs found
Osservazioni preliminari sull'impiego delle somme termiche di sviluppo per il controllo di Aonidiella aurantii (Mask.) in Sardegna
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Strategic Determinants of Terminal Operating System Choice: An Empirical Approach using Multinomial Analysis
No full textAbstractContainer terminal operators have at their disposal several operational options for performing both the transfer and the handling of containers. Traditionally, the determinants of the choice of operating systems have been investigated almost exclusively from a technical point of view, while limited research has been performed in the area of the strategic determinants of such choice.This study tries to investigate the strategic determinants of the operating system choice from an empirical perspective. Special attention is paid to understanding in which measure restrictive and limiting labour regimes can explain the preference for emerging automated models or, more in general, for less labour intensive concepts. A sample consisting of 65 European container terminals is built. For each terminal taking part in the sample the major determinants of the operations concepts are quantified. The use of logistic regressions provides interesting insights on what strategically motivates the choice of an operating system with respect to another, in order to investigate and discuss important managerial and policy implications
Maritime Supply Chain Security: A critical review
No full textThe importance of container security for international trade is well established and has been the subject of recent research in the follow up of the implementation of global security initiatives and the imperative of avoiding supply chain disruptions and reduce vulnerability. This article provides a review of the emerging literature on container security specifically in its interface with global logistics systems. The paper highlights the topics that have emerged as well-established research areas and indicates in what areas scholarly attention is most needed
Key exchange using Chebychev polynomials
No full textWe propose a variant of the well known Diffie-Hellman algorithm which uses Chebychev polynomials
On quaternion algebras that split over specific quadratic number fields
No full textLet d and m be two distinct squarefree integers and (9K the ring of integers v/ of the quadratic field K = Q( d). Denote by HK(a, m) a quaternion algebra over K, where a E (9K. In this paper we give necessary and sufficient conditions for HK(a, m) to split over K for some values of a, and we obtain a complete characterization of division quaternion algebras HK(a, m) over K whenever a and m are two distinct positive prime integers. Examples are given involving prime Fibonacci numbers
Potential and limiting factors in the use of alternative fuels in the European maritime sector
No full textThe maritime sector is a key asset for the world economy, but its environmental impact represents a major concern. The sector is primarily supplied with Heavy Fuel Oil, which results in high pollutant emissions. The sector has set targets for deacrbonisation, and alternative fuels have been identified as a short-to medium-term option. The paper addresses the complexity related to the activities of the maritime industry, and discusses the possible contribution of alternative fuels. A sector segmentation is proposed to define the consumption of each sub-segment, so to compare it with the current alternative fuel availability at European level. The paper shows that costs and GHG savings are fundamental enablers for the uptake of alternative fuels, but other aspects are also crucial: technical maturity, safety regulation, expertise needed, etc. The demand for alternative fuels has to be supported by an existing, reliable infrastructure, and this is not yet the case for many solutions (i.e. electricity, hydrogen or methanol). Various options are already available for maritime sector, but the future mix of fuels used will depend on technology improvements, availability, costs and the real potential for GHG emissions reduction.(c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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