Chenhao Zhou

A simulation study for next generation transshipment port

As the global container logistics, especially the transshipment services, keep increasing, substantial improvements on both port storage capacity and port throughput rate are necessary. Besides, the future challenges of getting skilled labor and the rising labor cost have been bothering port operators. Automated Container Terminal (ACT) is a promising solution to these challenges. This study firstly introduced two new conceptual transshipment hub designs. Then the simulation models were designed respectively and the analytical results revealed pros and cons for both systems. Besides, the land utilization and capacity of two ACTs have also compared among advanced contemporary ports in the world.

An introduction and performance evaluation of the GRID system for transshipment terminals

While the global container trade, especially transshipment, keeps growing rapidly, land scarcity and sustainability pose severe challenges to port operators. To maintain their competitiveness, they have to maximize land utilization and improve productivity. As applications of the GRID (Goods Retrieval and Inventory Distribution) system prototype proposed by BEC Industries LLC, this paper discusses two new designs—the single GRID system and hybrid GRID system—from different angles. In particular, the configuration and mechanism of the single GRID system are introduced with different layouts. Given the GRID structure, one of the most critical aspects of the proposed architecture is the high incidence of conflicts among transfer units (TUs). Hence, the authors identify different conflict scenarios and subsequently provide the TU control logic to avoid conflicts. A simulation study then investigates the performance of the single GRID system and its robustness with respect to horizontal and vertical expansion. Due to the limitations of the single GRID system, the hybrid GRID system is then proposed and simulated for terminals demanding huge capacity and productivity. A new flexible and scalable simulation model is designed for the new system. Both the results on land utilization and productivity show that the hybrid GRID system is promising for future transshipment terminals.

Frame Trolley Dispatching Algorithm for the Frame Bridge Based Automated Container Terminal

This paper studies the container handling process for a newly designed container terminal, known as the Frame Bridge based Automated Container Terminal (FB-ACT). The system was shown to be an effective solution to the next generation container terminal, but its efficiency depends on the dispatching of frame trolleys (FTs), which transport containers along the apron. We address the FT dispatching problem to ensure conflict-free movements, while considering the handshakes with other devices in the system. A mixed-integer programming (MIP) model is formulated to minimize the makespan considering FT conflicts and handshakes. An algorithm based on filtered beam search is developed to solve the problem. In this algorithm, two filtering approaches are used to guide the search for beam nodes at each level. The first approach uses a surrogate model to effectively screen out the less promising nodes. Then, the second approach uses a reduced MIP model to further identify the beam nodes for the next level. Numerical ...

Information-Based Allocation Strategy for GRID-Based Transshipment Automated Container Terminal

In this paper, we introduce a storage allocation strategy for a transshipment container hub using a new automated container terminal called the hybrid GRID system. This study provides a novel approach of developing an efficient storage allocation strategy for new terminal concepts so that the complex formulations can be approximated by simple functions that can be quickly computed. Specifically, the storage allocation strategy is derived from an optimal allocation decision learned from a Mixed Integer Programming (MIP) model. Some input parameters of the MIP model are collected from a simulation model. An index measuring the storage location convenience is proposed and we regress this index with important variables to build an empirical model that provides recommendations on where to allocate containers to storage locations. The advantage of using the empirical approach is that it allows for fast computation which is expected in the dynamic and uncertain port environment. Numerical results show that four ...

Capacity planning for mega container terminals with multi-objective and multi-fidelity simulation optimization

ABSTRACT Container terminals play a significant role as representative logistics facilities for contemporary trades by handling outbound, inbound, and transshipment containers to and from the sea (shipping liners) and the hinterland (consignees). Capacity planning is a fundamental decision process when constructing, expanding, or renovating a container terminal to meet demand, and the outcome of this planning is typically represented in terms of configurations of resources (e.g., the numbers of quay cranes, yard cranes, and vehicles), which enables the container flows to satisfy a high service level for vessels (e.g., berth-on-arrivals). This study presents a decision-making process that optimizes the capacity planning of large-scale container terminals. Advanced simulation-based optimization algorithms, such as Multi-Objective Multi-Fidelity Optimization with Ordinal Transformation and Optimal Sampling (MO-MO2TOS), Multi-Objective Optimal Computing Budget Allocation (MOCBA), and Multi-Objective Convergent Optimization via Most-Promising-Area Stochastic Search (MO-COMPASS), were employed to formulate and optimally solve the large-scale multi-objective problem with multi-fidelity simulation models. Various simulation results are compared with one another in terms of the capacities over different resource configurations to understand the effect of various parameter settings on optimal capacity across the algorithms.

Inter-terminal transfer between port terminals. A continuous mathematical programming model to optimize scheduling and deployment of transport units.

In most large port cities, the challenge of inter-terminal transfers (ITT) prevails due to the long distance between multiple terminals. The quantity of containers requiring movement between terminals as they connect from pre-carrier to on-carrier is increasing with the formation of the mega-alliances. The paper proposes a continuous time mathematical programming model to optimize the deployment and schedule of trucks and barges to minimize the number of operating transporters, their makespan, costs and the distance travelled by the containers by choosing the right combination of transporters and container movements while fulfilling time window restrictions imposed on reception of the containers. A multi-step routing problem is developed where transporters can travel from one terminal to another and/or load or unload containers from a specific batch at each step. The model proves successful in identifying the costless schedule and means of transportation. And a sensibility analysis over the parameters used is provided. DOI: http://dx.doi.org/10.4995/CIT2016.2016.4149

A comprehensive study on new conceptual container handling system

With global transshipment trade increasing, new design solutions are required to keep the desired performance of the terminal. In this scope, this study introduces a new terminal solution, the Single GRID module (SGM). In order to scale the SGM we propose and compare two solutions: the Hybrid GRID (H-GRID) and the Extended GRID (E-GRID). Both implementations and the SGM use extensively simulation as a means to evaluate system performance. With H-GRID, we develop an integrated and modular concept. In this case, despite the routing is simplified to that of the SGM, the storage allocation problem becomes challenging. We propose an innovative index-based policy for allocation that is easily scalable to large systems and proves to be better than traditional rules. E-GRID scales up the SGM design by proposing a routing strategy to control the container flow within the yard and avoiding conflicts between Transfer Units (TU) travelling in opposite directions.