IMCC Special Session on Quantitative Analysis in Shipping and Aviation

Organized by the IMC-Frank Tsao Maritime Library and R&D Centre (IMCC) of The Hong Kong Polytechnic University (PolyU), this session starts with the topic “Quantitative Analysis in Shipping and Aviation” which is composed of three related studies. First, we discuss the modelling port call decisions of liner shipping services in a contestable market. Second, we examine the lifespan of world merchant fleet. Third, we analyze the stated preference on the heterogeneous behavior in airfare choice.

The number of ports to call is the essential information for liner service design, which also affects the decision on port development and capacity expansion. This study models the relationship between ship size and port call numbers in a contestable route with single or two players. In the single player model, the player determines the optimal number of port calls for a given contestable price. When there are two players, a duopoly model is development to model the optimal price discount and optimal number of port calls.

The service life of a ship is a fundamental information for ship-related decision. This study analyzes the lifespan of world merchant ships based on 16,551 ship deletion records since 1990 using Cox PH model. Important factors that affects ships life are identified in the study.

This study designed a comprehensive experiment to distinguish the different airfare selection behavior, and tested the validity and stability of the design using simulated data, and applied it in an actual survey on passenger behavior in air-fare selection. The result in such study can improve airlines’ revenue management strategy through better pricing.

LRC Special Session on Optimization for Logistics Applications

Organized by the Logistics Research Center (LRC) of The Hong Kong Polytechnic University (PolyU), this session includes four talks, which present new optimization methods for various logistics applications.

The first talk is about a real-world product distribution problem faced by a fast fashion retailer in Singapore. In this talk, a novel branch-and-price-and-cut algorithm will be presented based on a strong set-partitioning model, where an ad-hoc label-setting algorithm is designed to solve the pricing problem. Extensive computational results demonstrate the effectiveness and efficiency of the new algorithm.

In the second talk, a logistics problem in the aftermath of a Mass-Casualty Incident (MCI) will be discussed, for which a new response model will be proposed by considering the transportation resource and medical resource. Different from previous model, this new model assume that the capacity of each hospital as the number of operating rooms and take into account the treatment time for each patient. A mixed integer programming formulation is proposed and solved for the integrated optimization problem that taken into account patient to hospital assignment, ambulance dispatching, and treatment ordering.

In the third talk, a study on split delivery vehicle routing problem will be presented, where the demand of a customer needs to be served by a homogeneous fleet of vehicles with the minimum total traveling cost minimized. To tackle this difficult problem, a novel local search algorithm is proposed based on an effective approach to reduce the search space. The new algorithm has significantly outperformed the existing methods. Among the 113 benchmark instances tested, the new algorithm has improved the best-known solutions for 43 instances.

The session concludes with a study on a liner shipping network design problem that aims at creating a set of regular services for a designated fleet of oceangoing ships to transport the containerized cargos among seaports. A novel optimization approach is proposed based on simultaneous column and row generation. Results from experiments have shown the effectiveness and efficiency of our models and solution methods.