65 research outputs found
New solution approaches for the Train Load Planning Problem
The present paper faces the train load planning problem in container
terminals. The problem consists of assigning containers to rail wagons while maximizing the total priority of the containers loaded and minimizing the number of
rehandles executed in the terminal yard. Two diferent heuristic approaches, based
on an innovative way to compute weight limitations and on two 0/1 integer programming models, are proposed and compared on the basis of specifc key performance
indicators. The heuristic approaches are compared using random generated instances
based on real-world data. An extensive computational analysis has been performed
Simulation of novel algorithms to reduce truck congestion at container terminals
Efficient managing truck flows has become a challenge for container terminals that have to maintain a high productivity while guaranteeing high service levels to truckers. Moreover, the increasing quantity of cargo to be handled in short time windows introduces congestion and security issues. This paper deals with the definition and simulation of various algorithms implementing a truck management system, with the objective or reducing congestion outside and inside the terminal, so guaranteeing security standards. An extensive simulation campaign has been performed on real data sets provided by an important Italian container terminal, demonstrating the effectiveness of the proposed mathematical approach in reducing terminal congestion and security issues. The designed methodology is general enough to be effectively applied in other container terminals realities located worldwide
A rostering approach to minimize health risks for workers: An application to a container terminal in the Italian port of Genoa
The evolving safety regulation is pushing seaports to comply with safety measures for workers performing heavy loads handling and repetitive movements. This paper proposes a risk-aware rostering approach in maritime container terminals, i.e., it addresses the rostering problem of minimizing and balancing workers’ risk in such terminals. To this end, a mixed integer mathematical programming model incorporating workforce risks is proposed, considering constraints such as the satisfaction of the workforce demand to perform the terminal operations, the worker-task compatibility and restrictions on the sequence of tasks assigned to the same worker. The model has been successfully applied to plan workforce over a six months horizon in a real container terminal located in Northern Italy, the Southern European Container Hub (SECH) in Genoa. As the workforce demand in SECH terminal is available at most two weeks in advance, a rolling horizon planning approach is devised. Experimental tests on real data provided by SECH terminal over a six months planning horizon highlight the effectiveness of the approach - the maximum monthly risk for workers is reduced by 33.9% compared to the current planning – and suitability to other container terminal contexts. Moreover, the model is applicable to a broad range of port situations, and robust enough to need little adaptation
Combining multiple trips in a port environment for empty movements minimization
Road transportation represents the most used transportation mode to cover short distances. However, structural lack of planning and optimization in road transportation creates negative effects both for companies and for the social community, such as environmental pollution, economic loss and road congestion. These effects are mainly due to the fact that a lack of planning can yield the necessity of a huge number of empty trips. Usually trucks that pick up or deliver a full container in a port must return back the empty container to the place where the trip started, so performing one leg of the total trip without payload. The aim of the present paper is to propose a mathematical approach for combining multiple trips in a port environment (specifically, import, export and inland trips) by considering the opportunity of carrying two 20 ft containers simultaneously on the same truck and by using the same load unit if possible. In this way, in the same route, more than two nodes can be visited with the same vehicle thus significantly reducing the number of total empty movements. Time windows constraints related to companies and terminal opening hours as well as to ship departures are considered in the problem formulation. Moreover driving hours restrictions and trips deadlines are taken into account, together with goods compatibility for matching different trips. An experimental campaign based on real data is discussed in the paper
Using logistic redesigner (Lo.R.D.) software for designing and simulating a steel supply chain
This paper regards the analysis of the development of a logistics and transportation network concerning a steel plant. The main goal is to search for the best scenario that allows to supply the plant and to distribute all the finished products to final customers in the most efficient way. To this aim, a proper simulation
model has been developed and implemented utilizing Logistics Re Designer (Lo. R. D.) software. More specifically, three different transportation networks have been created: two “single” modal choice scenarios - by road or by rail – and an “intermodal” one. Another system variable regards the production capacity of the
steel plant: three different types of capacity have been considered; so in total nine scenarios have been taken
into consideration. The results obtained indicate that the intermodal solution is the most suitable to be adopted
both in terms of total time – and consequently costs - and resources required to perform all the necessary
operations. Future research will focus on the improvement of the solution found and on the development of an economical analysis
Study of an emergency situation using 2D and 3D simulation models
Safety in motorway tunnels has become a critical issue in the last years, especially after the accident happened in 1999 inside the Mont Blanc tunnel, causing 39 deaths and several dozens of intoxications and wounded people. After this tragic event, the European Union imposed stricter regulations and procedures for
emergency situations inside road tunnels longer than 1000 m. According to this situation, the authors propose the use of M&S (Modeling and Simulation) in order to manage a tunnel evacuation after a fire exploding in consequence to an accident, taking into account a series of significant factors like the road signs position (new criteria have been introduced with new regulation), but also human factors which significantly affect the procedure outcome. First a 2-D simulation model has been developed using Java™ Software, in which the user can analyze the behavior of the people escaping and the dynamics of the fire exploded and, consequently, assess the effectiveness of all the emergency procedures and infrastructures. In particular, regarding the state
variables related to the human behavior, the model takes into account the main aspects of PECS (Physical Emotional Cognitive Social) reference models, in which physical, emotional, cognitive and social factors have to be studied. The model presented in this work is in fact quite similar to the one described by (Schmidt, 2000), called “Adam’s World” where Adam, a primitive man, lives in an environment having food sources where he can replenish his energy level, but also traps and danger points to be avoided in order not to consume his energy faster. The aim of the two models is the same: first of all preserve life and health, but the great difference between Schmidt’s model and the authors’ one is that in Adam’s World the social aspect is missing (Adam live alone in his world), while in the evacuation model social aspects can significantly affect the individual’s decisions. Upstream of the evacuation model, a weighted analysis needs to be considered, in fact the individual has to operate different choices considering several aspects, like health or goods preservation,
familiar aspects, panic and so on. For this reason a suitable methodology has been detected: the Analytic
Hierarchic Process (AHP), implemented by the American mathematician Thomas Saaty, which introduced this
technique for Multi-Criteria Analysis. After the considerations on the individuals behavior based on the results
of the analysis, the evacuation model and its results are described and analyzed in the following sections and, in
the final part of the paper, a description of a 3-D tunnel model devoted to study in particular smoke dynamics is
provided, thus it is possible to evaluate the impact of the smoke on the flow of the people escaping from the tunnel
Assessing the Feasibility of MaaS: A Contribution from Three Italian Case Studies
Making all types of public and private transport services available to users through a single
and integrated digital platform is the new urban mobility paradigm called Mobility as a Service
(MaaS). This scheme allows both a more sustainable urban transportation system and a more efficient
transport service for users. For MaaS to be successful, its implementation should adapt to the specific
features of the location covered by the service. The city maturity level has to be considered in terms
of multimodality, infrastructures, regulations, user goals, and user willingness to use and pay for
MaaS services. This paper discusses and analyses the results of a survey on MaaS conducted in
three Italian metropolitan areas: Turin, Rome, and Genoa, which have very different and specific
characteristics. The comparative analysis enables the definition of drivers, obstacles, and requisites
for MaaS implementation to be successful. When it comes to cities with conservative mobility policies
or cities that are new to MaaS experiences, resistance to adoption of the service might occur. The
results of the research discussed in this paper can be a useful resource to enable decision makers to
develop more effective and efficient transportation policie
Il trasporto e la logistica in Italia durante l’emergenza Covid-19
L’articolo illustra in modo sintetico e comparato i dati di traffico nazionali relativi al trasporto delle merci ed alla logistica durante l’emergenza sanitaria Covid-19: un riepilogo non consueto. Al termine, vengono proposte alcune azioni che, talvolta, rientravano già in obiettivi di breve o medio termine del settore oppure fanno già parte di tavoli di lavoro operanti in tali ambiti. Tali azioni, alla luce di quanto occorso con l’emergenza sanitaria, sono ricollegabili alle analisi svolte ed alle maggiori consapevolezze di problematiche preesistenti che si possono trarre
Compliance of maintenance and operational needs for trains: a simulation analysis to evaluate the impact of a flexible scheduling on local transport by rail
If not properly managed neither planned on real needs, the maintenance of rolling stock may strongly affect rail operations in local public transport, risking to compromise the quality of service or generating an over sizing of the fleet. Therefore, an effective coordination is required between the Operation and Maintenance departments. Some flexibility in maintenance activities – i.e., preventive and on condition maintenance policies - has already been applied for some years in the regional rail transport with successful results; however, it has not been introduced yet in rail public transport, where a corrective maintenance is generally adopted. In this work, the proper scheduling of more flexible maintenance activities in the rail public transport context is addressed through the use of discrete event simulation.
Real data sets provided by the Italian GTT-Gruppo Torinese Trasporti company have been used to test the proposed approach and to carry out a multi-scenarios campaign, aiming at analyzing the effectiveness of the maintenance process when certain operating conditions change or unexpected events occur. Some improvement proposals have also been analyzed with the proposed simulation method
Augmented reality and portable devices to increase safety in container terminals: the testing of A4S project in the port of Genoa
Port container terminals are intrinsically complex environments and the human factor is often the main cause of accidents. Industry 4.0 technologies enable to dispose of enormous quantity of data, process them with advanced algorithms also allowing predictivity, and provide virtual/augmented reality tools to interact with human operators. Promising solutions are spreading that use the loT paradigm to acquire data and apply Big Data techniques to manage them.
The objective of “Awareness for Safey-A4S” project, is to test a complete solution that allows field operators to be equipped with intelligent wearable devices, allowing "conscious" interaction in complex environments. This solution provides for the visualization of environment information in real time through Augmented Reality devices. These devices themselves represent a "sensor" providing information to the general system. Such information, integrated with environmental data and gathered through a specific I-IoT cloud platform and customized field devices, can improve safety and effectiveness of operations. Further support for operator safety is provided by a route tracking system aimed at directing operators, walking in the terminal, on the shortest and safest path. Such system can consider in real time the risks due to the movements of terminal equipment. The current paper presents this solution and the first field tests at PSA SECH container terminal in the Italian port of Genoa port to demonstrate the effectiveness of the proposed solution in increasing safety in complex and dangerous environments
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