Evaluating impact of truck announcements on container stacking efficiency

Container stacking rules are an important factor in container terminal efficiency. We build on prior research and use a discrete-event simulation model to evaluate the impact of a truck announcement system on the performance of online container stacking rules. The information that is contained in the announcement, i.e., the expected departure time for an import container, can be used to schedule pre-emptive remarshall moves. These moves can then be performed when the workload is low in order to decrease the export time and the crane workload at peak times

Sea Container Terminals

Due to a rapid growth in world trade and a huge increase in containerized goods, sea container terminals play a vital role in globe-spanning supply chains. Container terminals should be able to handle large ships, with large call sizes within the shortest time possible, and at competitive rates. In response, terminal operators, shipping liners, and port authorities are investing in new technologies to improve container handling infrastructure and operational efficiency. Container terminals face challenging research problems which have received much attention from the academic community. The focus of this paper is to highlight the recent developments in the container terminals, which can be categorized into three areas: (1) innovative container terminal technologies, (2) new OR directions and models for existing research areas, and (3) emerging areas in container terminal research. By choosing this focus, we complement existing reviews on container terminal operations

Research into container reshuffling and stacking problems in container terminal yards

Container stacking and reshuffling are important issues in the management of operations in a container terminal. Minimizing the number of reshuffles can increase productivity of the yard cranes and the efficiency of the terminal. In this research, the authors improve the existing static reshuffling model, develop five effective heuristics, and analyze the performance of these algorithms. A discrete-event simulation model is developed to animate the stacking, retrieving, and reshuffling operations and to test the performance of the proposed heuristics and their extended versions in a dynamic environment with arrivals and retrievals of containers. The experimental results for the static problem show that the improved model can solve the reshuffling problem more quickly than the existing model and the proposed extended heuristics are superior to the existing ones. The experimental results for the dynamic problem show that the results of the extended versions of the five proposed heuristics are superior or similar to the best results of the existing heuristics and consume very little time

Neural Task Programming: Learning to Generalize Across Hierarchical Tasks

In this work, we propose a novel robot learning framework called Neural Task Programming (NTP), which bridges the idea of few-shot learning from demonstration and neural program induction. NTP takes as input a task specification (e.g., video demonstration of a task) and recursively decomposes it into finer sub-task specifications. These specifications are fed to a hierarchical neural program, where bottom-level programs are callable subroutines that interact with the environment. We validate our method in three robot manipulation tasks. NTP achieves strong generalization across sequential tasks that exhibit hierarchal and compositional structures. The experimental results show that NTP learns to generalize well to- wards unseen tasks with increasing lengths, variable topologies, and changing objectives.Comment: ICRA 201

A Comparison of Priority Rules for Non-passing Automated Stacking Cranes

A recent trend in container ports is to operate dual non-passing Automated Storage Cranes (ASCs) that collaborate to serve storage and retrieval requests from opposite ends of a storage block. Since the ASCs are unable to pass each other, there is an exchange zone that serves as a temporary storage location so that one crane can start a request and leave it to the other crane to complete it. In this study, twelve priority rules are introduced and evaluated to determine which rule minimizes the total makespan for serving all requests, given the sequence in which each ASC will serve the requests. Preliminary results from 12 randomly generated experiments indicate that the priority rules favoring the crane furthest away from the origin of the next request (LonOri) and the longest individual completion times (LonTot) outperformed all other rules in terms of the average percent difference with the best found solution and in terms of the percent of times the priority rule yield the best found solution. Also, combining priority rules AdvFun and LonRem yields the best makespan in 11 of the 12 (91.67%) problem instances tested. Results of this study transcend container ports as it is applicable to any material handling system composed of non-passing MHE and that has pickup/deposit points at the ends of the system

Off-peak truck deliveries at container terminals: the 'Good Night' program in Israel

Purpose – Avoiding truck congestion and peaks in landside activity is one of the challenges to container terminal managers. The spreading of truck arrivals at terminals can be facilitated by widening the opening hours of terminals at the landside. Israel’s Ministry of Transport has instituted the “Good Night Program”, involving monetary incentives for importers and exporters who deliver containers to ports at night. Design/methodology/approach – This paper aims to quantitatively examine the market utility resulting from shifting traffic from daytime to nighttime, and analyzes customer considerations regarding nighttime transportation. Findings – The external utility found in the traffic-economics model is quite similar to the economic incentive given to customers. Therefore, a significant increase of the incentive is not feasible. Originality/value – Furthermore, it seems that an incentive method by itself is not effective enough, and does not motivate customers to act and find creative solutions to the obstacles they face. To achieve a considerable change in nighttime transport to Israeli ports, more effective methods should be examined