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Double cycling is an efficient tool to increase the efficiency of quay crane (QC) in container terminals. In this paper, an optimization model for double cycling is developed to optimize the operation sequence of multiple QCs. The objective is to minimize the makespan of the ship handling operation considering the ship balance constraint. To solve the model, an algorithm based on Lagrangian relaxation is designed. Finally, we compare the efficiency of the Lagrangian relaxation based heuristic with the branch-and-bound method and a genetic algorithm using instances of different sizes. The results of numerical experiments indicate that the proposed model can effectively reduce the unloading and loading times of QCs. The effects of the ship balance constraint are more notable when the number of QCs is high.

Abstract The single pricing approach fails to reflect different demand changes in response to its cargo space prices at different sales periods. This might be an obstacle to maximize the cargo space revenue of air freight carriers. This paper conducts the empirical analysis on pricing strategies in the spot market for two competitive air freight transport carriers operating on the same segment. It concludes that two carriers gain more revenues with the optimized differential pricing approach than with the single pricing approach. In theory, the research enriches the current literature in terms of pricing strategy optimization under the competition of two parties. In practice, it provides references for air freight transport carriers in their decision-making of applying the differential pricing strategy. Highlights • Investigate the differential pricing strategy applied in the decision making of air freight transport carriers over multiple sales periods in the sport market. • The proposed differential pricing mode can obtain more revenues than the single pricing mode currently adopted in the spot market. • The demand for air freight transport in the spot market has a low elasticity of price. • A higher competition level gives more room for two air freight transport carriers to increase their prices simultaneously. [ABSTRACT FROM AUTHOR]

A unique commercial operation in China that delivers express parcels within the storage compartments (belly-holds) of highway passenger coaches is introduced. A new delivery mode, called ‘direct + transfer’ delivery, is proposed. On the basis of this mode, a model to optimize the delivery path is constructed by considering the parcel arrival patterns, coach departure times, and belly-hold capacity in the initial origin. The solution algorithm is designed. In a case study, the probability distribution function of the parcel arrival pattern is fitted, and the delivery paths of parcels from a city to other cities in a region in China are calculated and analyzed. [ABSTRACT FROM AUTHOR]

Dalian used to have a very favorable modal split (for public transport) and had the honor of being an environmentally friendly city among its peers in China only a few years ago. However, momentous and when it comes to sustainability rather deleterious is evolving in the past five years or so: automobiles have flooded the city along with car-friendly policies being promulgated at both the central and local levels of government. Consequently, the market share of public transport has been substantially eroded since then. Apart from the rapid motorization that weakened Dalian's position as a green city, another factor fueling the downward trend o transit attractiveness has been the growing fragmentation in transit services. Given the fact that the motorization process is irreversible and restricting car purchase and use is unlikely to work out in China, if something needs to be done to maintain Dalian as a clean and comfortable living habitat, then lifting the fragmentation in the transit system is the only way to do this. Therefore, this paper explores where the fragmentation originates, and how it can be counteracted. A mathematical model is thus built to test the effectiveness of reducing fragmentation in improving transit service. And the results show that the modal split after system integration is going to tilt more strongly towards transit, while for service quality levels for users cannot expect much improvement. These modeling results have significant implications for the future public transport administration in Dalian. [ABSTRACT FROM AUTHOR]

Dynamic vehicle dispatching at the transfer station can improve the transit service quality by optimizing the transfer coordination of routes. In this paper, a dynamic vehicle dispatching model is proposed that aims to minimize the total waiting time of passengers at the transfer station and the downstream stops. A prediction model based on support vector machines (SVM) is also developed to forecast the arrival time of the next vehicles at the transfer station. To reduce the disconnected cases between the transfer routes, an SVM-based model is introduced to forecast the elastic time for the estimated arrival time at the transfer station. According to the estimated arrival time and elastic time, vehicles are dispatched in a dynamic way to reduce the total waiting time of passengers. The dynamic vehicle dispatching approach at the transfer station is examined with the data of three transfer routes in the city of Dalian, China. Results show that the approach proposed in this paper can reduce the total waiting time of passengers at the transfer station and the downstream stops. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a model for optimizing bus route headway is presented in a given network configuration and demand matrix, which aims to find an acceptable balance between passenger costs and operator costs, namely the maximization of service quality and the minimization of operational costs. An integrated approach is also proposed in the paper to determine the relative weights between passenger costs and operator costs. A parallel genetic algorithm (PGA), in which a coarse-grained strategy and a local search algorithm based on Tabu search are applied to improve the performance of genetic algorithm, is developed to solve the headway optimization model. Data collected in Dalian City, China, is used to verify the feasibility of the model and the algorithm. Results show that the reasonable resource assessment can increase the benefits of transit system. [Copyright &y& Elsevier]

In this paper, a bilevel programming model for the bus frequency design is presented, which determines the optimal bus frequencies aiming to minimize the total travel time of passengers subject to the constraint on the overall fleet size of each company by accounting for the route choice behaviors of the users. The objective of the lower level is to assign transit trips to bus route network based on optimal strategy. In the upper level, bus frequencies of routes are optimized as a result of passenger assignment. An iterative approach, which consists of a genetic algorithm and a label-marking method, is used to solve the bilevel model. Finally, the model and the algorithms are illustrated with two test examples. The results show that the optimization can improve the local service level of one company, and the proper integration of several companies probably improves the efficiency of resources and the service level of the whole transit system. [ABSTRACT FROM AUTHOR]

Abstract: This study forecasts the maximum car ownership in a city that is consistent with environmental sustainability. A bi-level optimization model is used, where upper-level establishes car ownership consistent with the maximum environmental load on the road network, while the lower level assigns traffic demand across the network. Modal split and traffic environmental load models are used to connect the two levels. An algorithm, embracing sensitivity analysis (an acquiring derivative function of link flow and traffic demand with respect to zonal car ownership) is developed. To estimate the traffic environmental load accurately, an artificial neural network model is used to calculate the pollutants concentrations along the roads. [Copyright &y& Elsevier]

Effective prediction of bus arrival time is central to many advanced traveler information systems. This article presents support vector machines (SVM), a new neural network algorithm, to predict bus arrival time. The objective of this paper is to examine the feasibility and applicability of SVM in vehicle travel time forecasting area. Segment, the travel time of current segment, and the latest travel time of next segment are taken as three input features. Bus arrival time predicted by the SVM is assessed with the data of transit route number 4 in Dalian economic and technological development zone in China and conclusions are drawn. [ABSTRACT FROM AUTHOR]

The port integration problem in a multi-port region (MPR) is studied from the perspective of maximizing the social welfare of the external transport system in a closed region in which the ports are regarded as external transport hubs. First, the economic principle of maximizing the social welfare of the external transport system is analyzed, and a method to calculate the total internal transport cost of the external transport system is proposed. Second, the optimal scale of the port group in an MPR is determined by comparing the total internal costs for different scales of the port group. An integration method with multi-period investment and asset idling is also proposed that takes into account excess port resources in MPRs. Finally, main gateway ports in Northeast China are selected for an empirical study. Based on the findings, suggestions regarding port resource integration and cooperative operation in MPRs are presented. [ABSTRACT FROM AUTHOR]

This paper introduces an optimization model (COSDM) for a Container Ocean-transportation System with the objective of maximizing the revenue of a liner company while taking into account the seasonal fluctuation in transportation demand and the choice inertia of shippers. The COSDM optimizes shipping network design and fleet deployment simultaneously, and it optimizes plans for changing the shipping network and for distributing slots in ships based on the fluctuation in demand and the characteristics of the shippers’ choice inertia. To solve COSDM, a heuristic algorithm is created that combines Genetic Algorithm and Simplex Method. The results show that the COSDM gives an optimized design scheme of the system that takes into account the stability of transportation services and improves the user experience of shippers while increasing the revenue of the liner company. Moreover, the results also reveal new explanations for the increasing size of container ships. [ABSTRACT FROM AUTHOR]