8,231 research outputs found

    Modelling the impact of liner shipping network perturbations on container cargo routing: Southeast Asia to Europe application

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    Understanding how container routing stands to be impacted by different scenarios of liner shipping network perturbations such as natural disasters or new major infrastructure developments is of key importance for decision-making in the liner shipping industry. The variety of actors and processes within modern supply chains and the complexity of their relationships have previously led to the development of simulation-based models, whose application has been largely compromised by their dependency on extensive and often confidential sets of data. This study proposes the application of optimisation techniques less dependent on complex data sets in order to develop a quantitative framework to assess the impacts of disruptive events on liner shipping networks. We provide a categorization of liner network perturbations, differentiating between systemic and external and formulate a container assignment model that minimises routing costs extending previous implementations to allow feasible solutions when routing capacity is reduced below transport demand. We develop a base case network for the Southeast Asia to Europe liner shipping trade and review of accidents related to port disruptions for two scenarios of seismic and political conflict hazards. Numerical results identify alternative routing paths and costs in the aftermath of port disruptions scenarios and suggest higher vulnerability of intra-regional connectivity

    Smart Technologies for Environmental Safety and Knowledge Enhancement in Intermodal Transport

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    International concerns about security in transport systems are leading to a new international regulation in this field. This introduces new requirements for operators and authorities as well as it opens new challenges, in particular when referred to seaports and maritime transport in the Mediterranean area, where many seaport terminals and infrastructures are affected by a noteworthy technological divide from North European contexts. In such contexts, the adoption of the new regulations can represent the right chance for upgrading the local operative standards, increasing latu sensu the quality of maritime transport performances, while conferring a greater level to security and safety checks. This paper explores the chances for increasing the level of Mediterranean seaport competitiveness allowed by technological innovations in transport systems, both in operations and organization of these infrastructures. The aim of the work is to study the effects of the adoption of technological solutions such as wireless communications and radiofrequency identification on the competitiveness of Mediterranean seaport infrastructures. Technological solutions designed to identify good items help operators in organizing activities in terminals and make maritime transport faster in delivering goods, by cutting the handling time and costs in seaport terminals. Seaports that adopt this kind of technologies, and the surrounding economic areas connected to seaports, have a greater attractiveness on shipping companies and operators, since they allow faster handling activities and easier checks on goods. Besides, the analysis of direct and indirect effects of the use of such technologies specifically focuses on the contribution that the use of these solutions gives in ensuring higher security levels, by increasing the level of information and knowledge associated to goods. The different types of security provided (e.g. for people, environment and goods) and the extreme flexibility of the technologies involved give the overall worth of the challenge. It seems to be a great chance of growth for the Mediterranean area, more than a mere compliance to the international security regulations.

    Analysing trade-offs in container loading: Combining load plan construction heuristics with agent-based simulation

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    This is the accepted version of the following article: Analysing Trade-offs in Container Loading: Combining Load Plan Construction Heuristics with Agent-based Simulation. International Transactions in Operational Research, 20(4): 471-491which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/itor.12017/abstractIn this paper we describe two operations research techniques, cutting and packing optimisation (CPO) and simulation, and present a multi-methodology approach for analysing the trade-offs between loading efficiency and various important practical considerations in relation to the cargo, such as its stability, fragility or possible cross-contamination between different types of items over time. The feasibility of this approach is demonstrated by considering a situation where the items to be loaded have differing degrees of perishability and where badly deteriorated items can affect those in their immediate vicinity (e.g. through the spread of mould). Our approach uses the output of the CPO algorithms to create agents that simulate the spread of mould through proximity-based interactions between the agents. The results show the trade-offs involved in container utilisation and the propagation of mould, without evidence of any correlation between them. The contribution of this research is the methodology and the feasibility study

    An intercompany dispatch support system for intermodal transport chains

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    A critical problem in an intermodal transport chain is the direct meet at the transhipment nodes. This requires information technology and modern communication facilities as well as much closer collaboration between all the concerned transport operators in the chain. The TELETRUCK system - currently under development at the German Research Center for Artificial Intelligence (Deutsches Forschungszentrum fĂĽr KĂĽnstliche Intelligenz DFKI GmbH) - is a dispatch support system that tackles those problems. Intercompany planning, scheduling, and monitoring of intermodal transport chains will be supported by our system. It aims at providing smooth access to railway time tables and rail-based transport services and - much more important - at allowing for the planning of both, exclusively road-based and combined journeys and showing their cost-effectiveness, where- and whenever possible. We will describe our approach - based on intelligent agent technology - both the current state of implementation and our goal of the very next future

    Rescheduling policies for large-scale task allocation of autonomous straddle carriers under uncertainty at automated container terminals

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    This paper investigates replanning strategies for container-transportation task allocation of autonomous Straddle Carriers (SC) at automated container terminals. The strategies address the problem of large-scale scheduling in the context of uncertainty (especially uncertainty associated with unexpected events such as the arrival of a new task). Two rescheduling policies-Rescheduling New arrival Jobs (RNJ) policy and Rescheduling Combination of new and unexecuted Jobs (RCJ) policy-are presented and compared for long-term Autonomous SC Scheduling (ASCS) under the uncertainty of new job arrival. The long-term performance of the two rescheduling policies is evaluated using a multi-objective cost function (i.e., the sum of the costs of SC travelling, SC waiting, and delay of finishing high-priority jobs). This evaluation is conducted based on two different ASCS solving algorithms-an exact algorithm (i.e., branch-and-bound with column generation (BBCG) algorithm) and an approximate algorithm (i.e., auction algorithm)-to get the schedule of each short-term planning for the policy. Based on the map of an actual fully-automated container terminal, simulation and comparative results demonstrate the quality advantage of the RCJ policy compared with the RNJ policy for task allocation of autonomous straddle carriers under uncertainty. Long-term testing results also show that although the auction algorithm is much more efficient than the BBCG algorithm for practical applications, it is not effective enough, even when employed by the superior RCJ policy, to achieve high-quality scheduling of autonomous SCs at the container terminals. © 2013 Elsevier B.V. All rights reserved

    Analysis of Port Community System Introduction in Croatian Seaports - Case Study Split

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    The introduction of a Port Community System (PCS) is identified as one of the key elements facilitating seaport development. In this paper, the analysis of seaport stakeholders and Maritime Single Window systems in Croatia is performed, including NSW (National Single Window), MNSW (Maritime National Single Window: CIMIS - Croatian Integrated Maritime Information System), their interaction and development of the national model for a PCS, ongoing in the form of a pilot project in the Port of Rijeka. This development is selected as a precedent for creation of the nation-wide PCS to be used also in other cargo ports of national interest, including Split. Further building on this newly gained knowledge and taking into consideration the development of the national PCS model, we explain the inherent characteristics of the Port of Split in terms of traffic evaluation in various port basins. We also provide a comprehensive set of operative guidelines for adjustment of the functional PCS module architecture to be deployed in the Port of Split and serving specific business needs of all identified port cluster’s stakeholders after the initial development in the Port of Rijeka is completed

    Contributions to behavioural freight transport modelling

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    Identifying Security-Critical Cyber-Physical Components in Industrial Control Systems

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    In recent years, Industrial Control Systems (ICS) have become an appealing target for cyber attacks, having massive destructive consequences. Security metrics are therefore essential to assess their security posture. In this paper, we present a novel ICS security metric based on AND/OR graphs that represent cyber-physical dependencies among network components. Our metric is able to efficiently identify sets of critical cyber-physical components, with minimal cost for an attacker, such that if compromised, the system would enter into a non-operational state. We address this problem by efficiently transforming the input AND/OR graph-based model into a weighted logical formula that is then used to build and solve a Weighted Partial MAX-SAT problem. Our tool, META4ICS, leverages state-of-the-art techniques from the field of logical satisfiability optimisation in order to achieve efficient computation times. Our experimental results indicate that the proposed security metric can efficiently scale to networks with thousands of nodes and be computed in seconds. In addition, we present a case study where we have used our system to analyse the security posture of a realistic water transport network. We discuss our findings on the plant as well as further security applications of our metric.Comment: Keywords: Security metrics, industrial control systems, cyber-physical systems, AND-OR graphs, MAX-SAT resolutio
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