A metamodelling approach for performance evaluation of intermodal transportation networks

The paper proposes a metamodelling procedure devoted to provide a reference model to be used by decision makers in the performance evaluation of Intermodal Transportation Network (ITN). In order to obtain a generic model describing a nonspecific ITN from the structural and behavioural point of view, the metamodelling approach consists in applying a top down and modular procedure. The model is specified by the well known Unified Modelling Language (UML), a graphic and textual modelling formalism intended to describe systems from structural and dynamics viewpoints. Hence, the paper models a generic ITN starting from the network description and shows by a case study the metamodel of one of the most important nodes that compose it: the port subsystem. Moreover, the case study model is translated in a simulation software and the performance measures obtained by the simulation results are shown

Simulation of railroad terminal operations and traffic control strategies in critical scenarios

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Models and Methods for Multi-Actor Systems

2010/2011The study of the models and methods to apply to multi-actor systems is a widely discussed research topic in the related scientific literature. The multi-actor systems are defined as systems that are characterized by the presence of several autonomous elements, of different decision makers and of complex rules that allow the communication, the coordination and the connection of the components of such systems. Commonly, the study of Multi-Actor System, MAS, recalls the well-known issues concerning the multi-agent systems. The research topic related to the multi-agent system firstly started to appear in scientific literature in 1980s, mainly in relation to the computer science and artificial intelligence. In this dissertation, in particular, the study of the multi-agent systems, and specifically of the multi-actor systems, is taken into account merely in relation to the distinctive features of complexity that characterize such systems and not to the issues concerning the agent-oriented software engineering. Therefore, the research results presented in this thesis are focused on the development and on the realization of innovative models and methodologies to face the management and the decision making mechanisms applied to complex multi-actor systems. This dissertation especially focuses on two different examples of multi-actor systems in two very diverse perspectives. The former deals with the research problem related to intermodal transportation networks, while the latter with the so called consensus problem in distributed networks of agents. Concerning the research problem related to the intermodal logistic systems, the research activity addresses the management of their more and more increasing complexity by the applications of the modern Information and Communication Technologies (ICT) tools that are key solutions to achieve the efficiency and to enhance logistics competitiveness. The related scientific literature still seems lacking in addressing with adequate attention the impact of these new techniques on the management of these complex systems and, moreover, there is an apparent lack of a systematic and general methodology to describe in detail the multiplicity of elements that can influence the dynamics and the corresponding information and decision making structure of intermodal transportation systems. The innovative results presented in this dissertation are focused on the development of an Integrated System, IS, devoted to manage intermodal transportation networks at the tactical as well as operational decision level to be used by decision makers both in off-line planning and real time management. To specify the Integrated System, a reference model is developed relying on a top-down metamodeling procedure. These innovative research results are a contribution to bridge the gap and to propose not only a systematic modeling approach devoted to describe a generic multi-actor logistic system, but also a management technique based on a closed loop strategy. The second example of application is focused on a topic that is widely discussed in scientific literature related to the study of the multi-actor collective behaviors in a distributed network. The interaction protocols that allow the agents to reach the convergence to a common value is called consensus or agreement problem. This research problem is particularly studied in the context of cooperative control of multi-agent systems because the agents are autonomous, independent and have to interact in a distributed network. The presented research results address the investigation of new and fast alignment protocols that enhance the performances of the standard iteration protocols for particular topologies of digraphs on the basis of a triangular splitting of the standard iteration matrix. The examined examples, the models and the methodologies applied to analyze them, are very different in the two cases and this testifies the large extent of research problems related to the multi-actor systems.L’analisi di modelli e metodi da sviluppare e da applicare nel contesto dei sistemi multi-attoriali costituisce un tema molto variegato e discusso nella letteratura scientifica internazionale. I sistemi multi-attoriali sono sistemi che si contraddistinguono per la presenza di molti elementi autonomi diversi tra loro, di molteplici decisori e di complesse regole che determinano la comunicazione, il coordinamento e la connessione all'interno di tali sistemi. Frequentemente, facendo riferimento a sistemi multi-attoriali, Multi-Actor Systems, si richiama il tema molto attuale dei sistemi multi agente, Multi-Agent Systems. Diffusisi a partire dal 1980, i sistemi multi agente sono spesso studiati in relazione alle metodologie di sviluppo dell'ingegneria del software. Nel presente lavoro di tesi, il tema dei sistemi multi-agente, ed in particolare di quelli multi-attoriali, non viene analizzato in questo contesto, ma in relazione alle tecniche decisionali da adottare per gestire sistemi caratterizzati da un alto livello di complessità. In tale ambito, i risultati presentati all'interno di questa dissertazione sono focalizzati sullo sviluppo e sulla realizzazione di nuovi metodi e di nuove metodologie, in grado di affrontare la gestione della complessità dei sistemi multi-attoriali. Vengono in particolare esaminate due diverse problematiche, in due contesti completamente diversi e con tecniche differenti, a testimoniare le vaste applicazioni che riguardano i sistemi multi-attoriali. I problemi analizzati sono incentrati, in primo luogo, su un'applicazione inerente la gestione di sistemi logistici intermodali ed, in secondo luogo, sullo studio delle regole o protocolli di interazione in una rete distribuita di agenti autonomi. Per quanto riguarda l'aspetto legato ai sistemi intermodali di trasporto, un tema molto discusso nella letteratura scientifica recente, l'analisi si focalizza sulla gestione della loro sempre crescente complessità, tramite l'utilizzo di sistemi dell'Information and Communication Technology, ICT. Questi strumenti richiedono metodi e modelli che sono innovativi rispetto a quanto è presente nella letteratura scientifica, all'interno della quale è stata riscontrata la mancanza di un approccio sistematico e sufficientemente ad alto livello per la realizzazione di una metodologia in grado di descrivere allo stesso tempo sia la molteplicità di elementi che influenzano le dinamiche e le informazioni, sia le strutture decisionali dei sistemi intermodali. L'innovazione dei risultati presentati in questa tesi si focalizza proprio sull'esigenza di proporre un sistema integrato, Integrated System (IS), basato su un metamodello delle reti intermodali di trasporto, che fornisca un valido supporto ai decisori sia a livello tattico che operativo. Il secondo aspetto affrontato in questa tesi riguarda un altro argomento di largo ed attuale interesse nella letteratura scientifica, che viene comunemente chiamato problema del consenso. Questo problema affronta lo studio di come diversi agenti autonomi collocati su una rete distribuita siano in grado di comunicare e di accordarsi su un valore comune, senza la presenza di un decisore centrale. A questo scopo ci sono degli algoritmi che specificano le regole o protocolli di interazione tra i diversi agenti. In tale contesto, i risultati proposti si focalizzano su alcune problematiche rappresentate dal protocollo classico del consenso e soprattutto sulla sua scarsa efficienza in particolari conformazioni delle reti di agenti. Il lavoro di tesi propone, quindi, un approccio di suddivisione, splitting, della matrice standard di iterazione, di tipo triangolare, che presenta notevoli vantaggi in termini di performance rispetto all'algoritmo classico. Lo studio di problemi multi-attoriali, pertanto, richiede lo sviluppo di innovative metodologie decisionali e di nuovi metodi di gestione delle comunicazioni, per rispondere al livello sempre crescente di complessità, offrendo in questo modo alcuni spunti molto interessanti per la ricerca.XXIV Ciclo198

Technical, economic and energetic competitiveness of rail-road combined transport: evaluation of the effects of possible ITS applications on intermodal terminal.

L'abstract è presente nell'allegato / the abstract is in the attachmen

AN ARTIFICIAL IMMUNE SYSTEM FOR PUBLIC TRANSPORT REGULATION

International audienc

A flexible platform for intermodal transportation and integrated logistics

This paper proposes an application of Information and Communications Technology (ICT) tools and Internet of Things to support intermodal transport and integrated logistics. In particular, the design and development of a new ICT platform is presented in order to facilitate the connectivity of the logistics systems, applications or objects from stakeholders to any logistics collaborative environment. The proposed platform aims to i) provide technological solutions to enhance and simplify collaboration among actors along the supply chain; ii) adopt and provide core functionalities to improve, optimise and automate transport and logistics operations within supply collaborations; iii) simplify information exchange within an integrated security framework. Finally, we show a case study in order to enlighten the effectiveness of the proposed ICT platform

Scheduled service network design with synchronization and transshipment constraints for intermodal container transportation networks

In this paper we address the problem of scheduled service network design for container freight distribution along rivers, canals, and coastlines. We propose a new concise continuous- time mixed-integer linear programming model that accurately evaluates the time of occurrence of transportation events and the number of containers transshipped between vehicles. Given the transportation network, the eet of available vehicles, the demand and the supply of containers, the sailing time of vehicles, and the structure of costs, the objective of the model is to build a minimum cost service network design and container distribution plan that denes services, their departure and arrival times, as well as vehicle and container routing. The model is solved with a commercial solver and is tested on data instances inspired from real-world problems encountered by EU carrier companies. The results of the computational study show that in scheduled service networks direct routes happen more often when either the eet capacity is tight or the handling costs and the lead time interval increase. The increase of the same parameters leads to the decrease of the number of containers transshipped between vehicles

Discrete-Event Control and Optimization of Container Terminal Operations

This thesis discusses the dynamical modeling of complex container terminal operations. In the current literature, the systems are usually modeled in static way using linear programming techniques. This setting does not completely capture the dynamic aspects in the operations, where information about external factors such as ships and trucks arrivals or departures and also the availability of terminal's equipment can always change. We propose dynamical modeling of container terminal operations using discrete-event systems (DES) modeling framework. The basic framework in this thesis is the DES modeling for berth and quay crane allocation problem (BCAP) where the systems are not only dynamic, but also asynchronous. We propose a novel berth and QC allocation method, namely the model predictive allocation (MPA) which is based on model predictive control principle and rolling horizon implementation. The DES models with asynchronous event transition is mathematically analyzed to show the efficacy of our method. We study an optimal input allocation problem for a class of discrete-event systems with dynamic input sequence (DESDIS). We show that in particular, the control input can be obtained by the minimization/maximization of the present input sequence only. We have shown that the proposed approach performed better than the existing method used in the studied terminal and state-of-the-art methods in the literature

Процедури моделювання логістичних транспортних систем у середовищі мереж Петрі

The article presents the methodology of the logistic system simulation into the Petri Nets environment on the example of agro-products delivery from Ukraine to the Netherlands, as well as a set of case-studies that can be used as didactic means for course “The modeling of transport processes” to teach the future transport industry specialists. The content, features and capabilities of the Petri Nets in the logistics systems simulation have been analyzed. A structural logistic system model of agro-products delivery, which takes into account the operation sequence, the combination peculiarities and the use resources in each subsystem, has been constructed into the Petri Nets. A time criterion has been proposed to determine the effective option for agro-products delivery. According to the results of the logistics system simulation into the Petri Nets environment, a statistical analysis of the parameters has been carried out. It has been made a choice of a suitable option of the delivery scheme allowing for the time spent and the magnitude of the possible costs associated with the use of certain transport modes. It has been made conclusion about feasibility of creating the case-study set, which is based on real facts and being solved into the Petri Nets environment, in order to organize the future transport industry specialists’ study and research activities.У статті представлена ​​методологія моделювання логістичної системи в середовищі Петрі-Мережі на прикладі доставки агропродукції з України до Нідерландів, а також набір тематичних досліджень, які можна використовувати як дидактичний засіб курсу «Моделювання транспортних процесів »для навчання майбутніх фахівців транспортної галузі. Проаналізовано зміст, особливості та можливості мереж Петрі у моделюванні логістичних систем. Модель структурної логістичної системи доставки агропродукції, яка враховує послідовність операцій, особливості поєднання та використання ресурсів у кожній підсистемі, була вбудована в мережі Петрі. Запропоновано критерій часу для визначення ефективного варіанту доставки агропродукції. За результатами моделювання логістичної системи в середовищі мереж Петрі було проведено статистичний аналіз параметрів. Було зроблено вибір відповідного варіанту схеми доставки, що враховує витрачений час та величину можливих витрат, пов'язаних із використанням певних видів транспорту. Було зроблено висновок про доцільність створення набору тематичних досліджень, який ґрунтується на реальних фактах і втілюється в середовище мереж Петрі, з метою організації навчально-дослідницької діяльності майбутніх фахівців транспортної галузі