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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design of a Quay Crane Training Simulator

Chen, Boyang, Xu, Mingyi January 2015 (has links)
No description available.
2

Vehicle Dispatching Problem at the Container Terminal with Tandem Lift Quay Cranes

Xing, Yao 16 December 2013 (has links)
The most important issue at a container terminal is to minimize the ship’s turnaround time which is determined by the productivities of quay cranes (QCs). The tandem lift quay cranes have 33% higher productivities than single lift QCs. However, the tandem lift operations bring new challenges to the vehicle dispatching at terminals and this has become a big issue in the application of tandem lift QCs. The vehicle dispatching at terminals is to enhance the QCs’ productivities by coordinating the QCs’ operation schedules and the vehicles’ delivery schedules. The static version of the problem can be formulated as an MILP model and it is a combinational optimization problem. When the type of QC is tandem lift, the problem becomes more complicated because it requires two vehicles side by side under the QC. Thus, the alignments of vehicles have to be considered by coordinating the delivery schedules between vehicles. On the other hand, because the containers are operated alone by the yard cranes, the vehicles could not be grouped and dispatched in pairs all the time. This dissertation investigates the static and dynamic version of the problem and proposes heuristic methods to solve them. For the static version, Local Sequence Cut (LSC) Algorithm is proposed to tighten the search space by eliminating those feasible but undesirable delivery sequences. The time windows within which the containers should be delivered are estimated through solving sub-problems iteratively. Numerical experiments show the capability of the LSC algorithm to find competitive solutions in substantially reduced CPU time. To deal with the dynamic and stochastic working environment at the terminal, the dissertation proposes an on-line dispatching rule to make real-time dispatching decisions without any information of future events. Compared with the longest idle vehicle rule, the proposed priority rule shortens the makespan by 18% and increases the QCs’ average productivities by 15%. The sensitivity analysis stated that the superiority of the priority rule is more evident when the availability of vehicles is not sufficient compared with the frequency of releasing transportation requests.
3

Optimalizační procesy v přístavním kontejnerovém terminálu

Stehlíková, Blanka January 2008 (has links)
Cíle diplomové práce jsou popsat procesy probíhající v kontejnerovém přístavním terminálu, vytvořit přehled rozhodovacích problémů vznikajících v kontejnerovém přístavním terminálu z hlediska úrovně jejich typu řízení a plánování (strategické, taktické a operativní) a formulovat vybrané rozhodovací problémy a matematicky je analyzovat.
4

Berth and quay crane scheduling: problems, models and solution methods

Ak, Aykagan 17 November 2008 (has links)
A comprehensive study on berth and quay crane scheduling problems at container terminals at seaports is provided. Problems related to both multi-user terminals, where the terminal operator and liner carriers are different parties, and dedicated terminals, where liner carriers lease the terminal, are considered. A lower bound and an effective meta-heuristic algorithm are proposed for a dynamic variant of the Berth Allocation Problem (BAP). The Multiple Berth Allocation Problem (MBAP) is also introduced. Different crane scheduling methods used by terminal operators are analyzed and a tabu search algorithm is designed for a new variant of the Quay Crane Scheduling Problem (QCSP). The Simultaneous Berth and Quay Crane Scheduling Problem (BQCSP) is introduced with a lower bound analysis and an efficient solution method. A computational analysis is performed which exposes the substantial benefit of simultaneous planning over the hierarchical approach currently used by terminal operators. The tactical level Voyage and Berth Scheduling Problem (VBSP) is defined and a mathematical model based on multi-commodity network flow is presented. Constraints related to transshipments, terminal time windows and service level requirements are incorporated into the model, and how to modify instance data to increase schedule reliability is discussed.

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