1,720,960 research outputs found
Un approccio alla progettazione operativa di un porto basato sulla simulazione: il caso di studio di Messina
No full textIl traffico marittimo passeggeri e merci è in continua crescita e la stima della capacità
di accoglienza dei porti risulta essere un fattore strategico al fine di garantire
una elevata qualità del servizio di trasporto navale; elemento chiave sia per la progettazione
dei layout portuali sia per la gestione del traffico (per esempio
l’assegnazione degli slot di attracco per gli arrivi e le partenze delle navi). Un approccio
classico si basa su modelli combinatori sintetici in grado di riprodurre la sequenza
dei movimenti delle navi in arrivo/partenza e di valutare il loro limite compatibile
con lo svolgimento delle operazioni in condizione di regolarità. In questo
contesto gli autori hanno sviluppato un modello di simulazione delle operazioni lato
mare basato su una piattaforma software flessibile e multiuso, strutturata per la stima
della capacità e l’analisi del traffico portuale e capace di supportare il processo di
progettazione e pianificazione operativa e mettere in relazione il grado di utilizzazione
con la qualità dei servizi portuali prodotti. L’articolo descrive il modello e le
sue prestazioni testato sul complesso caso studio del porto di Messina, che rappresenta
un nodo chiave del traffico marittimo del Mediterraneo, dovuto alla sovrapposizione
ai traffici di transito e di collegamento tra la Sicilia e la Penisola Italiana. I
risultati sono stati comparati con i dati reali di traffico e con i risultati ottenuti da un
modello combinatorio consolidat
Analisi e valutazione delle strategie di guida ecologica dei treni per la formazione del personale di condotta
No full textNell’ambito della crescente attenzione, a livello europeo, per la salvaguardia ambientale ed il risparmio energetico, ad esempio con gli obiettivi del Pacchetto
20-20-20, parte della Direttiva Europea 2009/29 [1], assume importanza lo studio dell’efficienza energetica nella condotta dei treni, nel quale confluiscono l’interesse per i temi ambientali e quello economico per l’ottimizzazione delle risorse. Il presente studio, svolto in collaborazione tra il Dipartimento di Ingegneria Civile Edile e Ambientale (DICEA) della Sapienza e Trenitalia, si articola in 2 macro attività: 1) analisi e valutazione dei profili di guida autonomamente adottati del personale di condotta, sulla base di cicli di guida reali e simulati; 2) analisi e valutazione dei profili di guida adottati in risposta ad un generico input di guida “energeticamente efficiente”.In the framework of increasing attention, at European level, for environmental protection and energy saving, represented by the objectives of the 20-20-20 Package, part of the European Directive 2009/29 [1], the study of energy efficiency in trains driving increase its relevance, whereas the interest in environmental and economic issues converge with resource optimization. This study, carried out in collaboration between the Department of Civil,
Building and Environmental Engineering (DICEA) of Sapienza University of Rome and Trenitalia, is divided into two macro activities: 1) analysis and assessment of the independently drivers’ driving profiles based on real and simulated driving cycles; 2) analysis and assessment of driving profiles adopted in response to a generic “energy-efficient” driving input
Discrete events simulation of Intermodal terminals operation. Modelling techniques and achievable results
No full textA freight intermodal terminal represents one of the most significant bottleneck in logistic chains. The discrete event simulation is suitable to represent the terminal operations, enabling the identification of strengths and weaknesses. It also permits the evaluation ahead of time the changes that modify organizations or the workability of terminals. In this paper the modelling process is described for a railroad terminal based on the simulation platform Planimate©. This platform is suitable to deal with systems articulated with plenty of data and sub-processes, to be managed in parallel and for synchronized cycles controlled according to a time run. The model is organised according to a hierarchical structure composed by various
subsystems: the highest level represents the layout of the terminal; the lower levels represent the operational areas, where the models manage integrated flows and elementary operations. Once the model has been built and is able to work, the achievable results are both in the field of operational management of the terminal (short-term application) and in the field of perspective analysis to check the feasibility and effectiveness of new scenarios, built by combining innovative technologies and operational measures (long-term application). The assessment of present and future scenarios is based on key performance indicators, which the model is able to calculate
Metodi analitici e modelli simulativi per la valutazione di misure operative e tecnologie innovative per i terminali ferroviari portuali: il caso del terminale di Valencia Principe Felipe
No full textLa ricerca descritta in questo articolo (sviluppata all’interno del progetto Europeo Ca-pacity4Rail) si focalizza sulla valutazione degli effetti che alcune innovazioni (ad esempio, movimentazione e immagazzinamento automatico orizzontale e parallelo, varchi automatici, sensori per lo scambio di dati e sistemi di tracciamento) possono portare nei terminali intermodali merci. La struttura metodologica utilizzata per valu-tare queste innovazioni si fonda sulla combinazione di metodi analitici basati su algo-ritmi sequenziali e modelli di simulazione ad eventi discreti. Il prodotto di questo me-todo di valutazione sono una serie di indicatori (KPIs) selezionati in base alla tipologia di terminale e relativi a differenti aspetti (ad esempio gestione, operazioni e organiz-zazione). Questo articolo illustra l’applicazione della struttura metodologica, rivolta alle operazioni di vari terminali intermodali, per la validazione delle operazioni odierne e la valutazione di possibili futuri scenari riferiti al caso di studio del terminale ferroviario portuale Principe Felipe di Valencia.The research work described in this paper (developed within the Capacity4Rail EU project) focusses on the assessment of effects that some innovations (e.g. automatic horizontal and parallel storage and handling, automated gate and sensors for data ex-change and tracking systems) can have in the intermodal freight terminals combined in various alternative scenarios. The methodological framework setup to assess these innovations is based on a combination of analytical methods based on sequential al-gorithms and discrete events simulation models. The output of this assessment method are Key Performance Indicators (KPIs) selected according to terminal typologies and related to different aspects (e.g. management, operations and organization). This pa-per illustrates the application of the methodological framework, tuned on the opera-tions of various intermodal terminals, for the validation on today operations and the assessment of possible future scenarios to the case study of the Principe Felipe sea-rail terminal in Valencia
Measuring Performances of Multi-mode Marshalling Yards
No full textThe chapter deals with the wagon-load freight transport. This kind of transport used to be the core business of railways during the last century, while in last decades it began to see its market share reduced in favor of other transport typologies (e.g. intermodal transport). Today wagon-load transport seems no longer economically viable and the smaller and medium volumes used majorly road vehicles and sometimes combined transport. One of many possible ways to try reversing the trend is to convert the old and increasingly frequent abandoned marshalling yards in technological terminals able to receive different kinds of trains equipped with different technologies. These terminals are the Multi-Mode marshalling yards (MMM). This definition refers mainly to the mode of transport and the different railway operation. In this paper are presented the most relevant results obtained through the modelling the operation of a real marshalling yard sited in Hallsberg, Sweden. There are under introduction some innovative technologies and operative measures to quantify the improvements in operations that could contribute to a recovery of the wagon-load transport, reducing the wagons mean transit time through the yards while increasing reliabilit
Present and future operation of rail freight terminals
No full textRail freight has not progressed coherently to economy: during the last century, the wagonload was the core business of railways, later declining in favor of combined transport, which include the notion of transshipment in an intermediate terminal. Terminals are a key element of transport services and, in this study, the main goal are methods suitable to evaluate the performances of different types of rail freight terminals: Rail to road for long distance and shorter range units transfer, Rail to rail for shunting and/or gauge interchange, Rail to waterways (sea and inland). The evaluation of the performances of terminals and the influence on them of innovative operational measures and technologies is based on a selected combination of tested analytical methods based on sequential application of algorithms and discrete events simulation models, capable to quantify different Key Performance Indicators
Analytical and simulation based methods for assessing measures and technologies capable to improve operation in railway freight terminals
No full textThe topic of freight transport by rail is a complex theme and, in recent years, a main issue of European policy. The legislation evolution, the White Paper 2011 and many research projects promoted by EU Commission, e.g. Capacity4Rail (C4R), have demonstrated the European intention to re-launch this sector. One of the main objectives of C4R Project is to improve the performances of railway freight transport to reduce the market share of road freight transport. In this context railway freight terminals play a primary role for the supply chain: they are the connection among the various transport modes and the nodal points where the freight are handled, stored and transferred or shunted to final customer. Objects of this paper are methods and main results achieved by the research group of DICEA within the C4R Project. The main objective is to contribute to the increase of rail freight traffic through the development of future freight terminals, based both on innovative operational measures (e.g. horizontal and parallel handling, faster and fully direct handling) and on innovative technologies (e.g. automatic system for horizontal and parallel handling, automated gate for data exchange, driverless locomotives). The research work focusses on the assessment of potential effects of these innovations in railway freight terminals. Operational measures and technologies compose different scenarios, to evaluate by a methodological approach including both analytical methods and simulation models. The output of this assessment methods are key performance indicators (KPIs), e.g. total/partial transit time, setup according to analysed terminal typologies and related to different aspects (e.g. management, operation and organization). Finally, in addition to illustrated methodological framework, some results on selected case studies include the intermodal Munich-Riem rail to road freight terminal (Germany), the Hallsberg marshalling yard (Sweden) and the intermodal Principe Felipe rail-sea freight terminal in Valencia port (Spain)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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