A new approach to the Container Positioning Problem

In this paper the Container Positioning Problem is revisited. This problem arises at busy container terminals and requires one to minimize the use of block cranes in handling the containers that must wait at the terminal until their next means of transportation. We propose a new Mixed Integer Programming model that not only improves on earlier attempts at this problem, but also better reflects reality. In particular, the proposed model adopts a preference to reshuffle containers in line with a just-in-time concept, as it is assumed that data is more accurate the closer to a container’s scheduled departure the time is. Other important improvements include a reduction in the model size, and the ability of the model to consider containers initially at the terminal. In addition, we describe several classes of valid inequalities for this new formulation and present a rolling horizon based heuristic for solving larger instances of the problem. We show that this new formulation drastically outperforms previous attempts at the problem through a direct comparison on instances available in the literature. Furthermore, we also show that the rolling horizon based heuristic can further reduce the solution time on the larger of these instances as well as find acceptable solutions to much bigger, artificially generated, instances.     

Aligning barge and terminal operations using service-time profiles

We consider a key issue in hinterland container navigation in ports, such as Rotterdam and Antwerp, namely the barge handling problem: how to optimize the alignment of barge and terminal operations in a port. We make a major step in solving the barge handling problem for practical settings. Specifically, we consider restricted opening times of terminals, unbalanced networks, the presence of sea vessels, and closing times of containers. Consequently, at a terminal a barge faces time dependency in: (1) the waiting time until the start of handling and (2) the handling time itself. The concept of waiting profiles which we introduced in an earlier paper only deals with (1). To deal with (1) and (2) together we introduce a more comprehensive concept, namely that of service-time profile. To establish how well our approach works, we evaluate the performance of our distributed planning approach extensively by means of simulation. We compare our results with those based on centralized planning by using an off-line benchmark resembling it. We show that the Multi-Agent system that we introduce enables barge and terminal operators to align their operations efficiently. Hence, it can be seen as a promising solution approach for solving the barge handling problem, since it enables (competing) companies to collaborate in a competitive way.     

Decision support based automatic container sequencing system using heuristic rules

Container terminals in seaports constitute interfaces between the seaborne transport and transport-over-land of goods in global transport chains. The loading and unloading of containers are performed using quay cranes (QCs), which is the most important equipment for handling servicing vessels at a container terminal. Following tremendous growth in global container transshipments, terminals are facing increasing demand. Terminals at Shanghai are equipped with Tandem Lift which can lift two 40’ containers simultaneously to improve the efficiency of the QCs. A reasonable container combinations of Tandem Lift and container operation sequence are required to improve the servicing of vessels, meanwhile the dual cycling container operation of quay cranes has to be investigated. This paper presents a two-stage mathematical model and two-level heuristic algorithm for planning the container operation sequence using Tandem Lift in a feasible computational time. Based on the proposed methodology, a decision support system, called the Tandem Lift Container Sequence System (TLCSS). A case study of Shanghai Shengdong International Port Company (SSICT) proves that consideration of the container sequence with Tandem Lift dramatically shortens servicing time of vessels with the TLCSS.     

Strategic allocation of cyclically calling vessels for multi-terminal container operators

We consider a terminal operator who provides container handling services at multiple terminals within the same port. In this setting, the well-known berth allocation problem can no longer be considered for each terminal in isolation since vessel calls should be spread over the various terminals to avoid peaks and troughs in quay crane utilization, and an allocation of two connecting vessels to different terminals will generate inter-terminal container transport. In this paper, we address the problem of spreading a set of cyclically calling vessels over the various terminals and allocating a berthing and departure time to each of them. The objectives are (1) to balance the quay crane workload over the terminals and over time and (2) to minimize the amount of inter-terminal container transport. We develop a solution approach based on mixed-integer programming that allows to solve real-life instances of the problem within satisfactory time. Additionally, a practical case study is presented based on data from the terminal operator PSA Antwerp who operates multiple terminals in the port of Antwerp, Belgium. The computational results show the cost of the currently agreed schedules, and that relatively small modifications can significantly reduce the required crane capacities and inter-terminal transport.     

Strategies for improving a long-established terminal’s performance: a simulation study of a Turkish container terminal

Due to a long-lasting increase in global trade, only interrupted by the late-2000s economic crisis, container traffic has grown dramatically. As a result, new terminals have opened and existing terminals face much higher container handling than before. In order to meet these challenges, one of the biggest container terminals in Turkey has begun to reconsider its terminal operations and to achieve improvements of its overall logistics performance. Because the factors impacting the terminal’s performance are highly interrelated, a simulation model was developed to analyze the terminal operations, to identify potential bottleneck resources and to highlight directions for the future development of the configuration and the operational control system. For a long-established terminal like the one considered in this study the options for improving the overall performance are limited by the geographical dimensions and by the existing terminal equipment. By use of the simulation model the terminal operations are evaluated under different workload scenarios and alternative configurations are tested in order to support strategic decisions on the terminal’s development.     

Inbound container storage price competition between the container terminal and a remote container yard

With the rapid development of global ocean transportation, storage space in container terminals is becoming a scarce resource. Hence, the terminal yard only performs as a temporary storage facility for inbound cargos. A storage charge is levied for inbound cargos that stay longer than a free storage time (called free-time-limit). After the free-time-limit, customers may move cargos from the terminal yard to a remote container yard where the storage price is lower than that in the terminal. This paper proposes inbound container storage pricing game models between the container terminal and a remote container yard. Two cases are considered: (1) the inbound container’s dwell time is random and follows a probability distribution function; (2) the inbound container’s dwell time is sensitive to the storage prices. The primary objective of this paper is to analyze the storage pricing behavior and competition outcomes of the container terminal and the remote container yard. A number of insights and analysis are provided.     

Pricing storage of outbound containers in container terminals

In container yard of container terminals, a storage charge is imposed to encourage customers to limit the space required for their containers. This study addresses the storage price scheduling problem for the storage of outbound containers. The price schedule consists of the free-time limit, which is the maximum duration for a container to stay in the yard without any charge, and storage charge per day for storing a container past the free-time-limit. Empirical data suggests that the efficiency of loading operations significantly depends on the space utilized by a vessel’s outbound containers. Mathematical models are developed to determine the optimal storage price schedule in such a manner that the terminal’s total profit is maximized or the total system’s cost is minimized. Both single and multi-vessel cases are considered. Properties of the optimal solution are derived from the mathematical models and numerical experiments are conducted to validate solutions.     

An analytical model for designing yard layouts of a straddle carrier based container terminal

In designing a yard layout for a container terminal several decisions have to be made. In this paper we propose a model which provides decision support for the design of yard layouts of terminals at which straddle carrier are used. We assume that straddle carriers are used for the horizontal transport and the stacking of containers. For the proposed model we develop estimates for the expected cycle distances of straddle carriers. In this case, we distinguish between cycles to landside facilities and to the quay. Numerical results are presented for several parameter settings. For instance, we present results for a comparison of layouts where the rows in the block are orientated parallel with layouts where the rows are orientated perpendicularly to the quay.     

A novel approach to yard planning under vessel arrival uncertainty

Many container terminals in the world adopt the consolidated yard planning strategy, where containers to be loaded into the same vessel are stacked in groups. This has been a good strategy because when a vessel is loading, yard cranes will be stationed at these locations, and the trucks shuttle between the quay cranes and the yard cranes almost in a conveyor belt fashion. These locations are optimally chosen such that no two groups of containers are stacked in close vicinity if they are to be loaded simultaneously. However, when there is a change in vessel arrival schedule, it may cause congestion of trucks at yard locations where groups of containers in near vicinity are loading simultaneously. While the Robust Optimisation community may suggest having a robust plan—a plan that is immune to uncertainty, in this paper, we will like to find a solution that allows us to change easily when uncertainty reveals—a plan that is nimble. While the optimum solution for the nimble plan could be intractable, we explore various heuristics that enable us to find good solutions.     

A cooperative quay crane-based stochastic model to estimate vessel handling time

Having a good estimate of a vessel’s handling time is essential for planning and scheduling container terminal resources, such as berth positions, quay cranes (QCs) and transport vehicles. However, estimating the expected vessel handling time is not straightforward, because it depends on vessel characteristics, resource allocation decisions, and uncertainties in terminal processes. To estimate the expected vessel handling time, we propose a two-level stochastic model. The higher level model consists of a continuous-time Markov chain (CTMC) that captures the effect of QC assignment and scheduling on vessel handling time. The lower level model is a multi-class closed queuing network that models the dynamic interactions among the terminal resources and provides an estimate of the transition rate input parameters to the higher level CTMC model. We estimate the expected vessel handling times for several container load and unload profiles and discuss the effect of terminal layout parameters and crane service time variabilities on vessel handling times. From numerical experiments, we find that by having QCs cooperate, the vessel handling times are reduced by up to 15 %. The vessel handling time is strongly dependent on the variation in the QC service time and on the vehicle travel path topology.     

Seaside operations in container terminals: literature overview,trends, and research directions

Seaside operations are considered the bottleneck operation in most container terminals around the world. This paper presents an in-depth updated overview of the seaside operations at container terminals and highlights current trends and developments. We review and classify scientific journal papers on container terminal seaside operations, published between 2004 and 2012. The paper also discusses and challenges the current operational paradigms on seaside operations. Lastly, the paper identifies new avenues for academic research based on current trends and developments in the container terminal industry.     

Toward a controllable headspace composition—Growth,development, and headspace of a micropropagatedPrunus rootstock in different containers

The body and closure device of a tissue culture container are of paramount importance in the determination of the headspace composition, and influence plant growth and development. In fact, the container determines gas exchange with the environment quantitatively and qualitatively. When exchange occurred via permeability, we demonstrated that a properly controlled container atmosphere (CA) cannot be obtained because accumulation and/or depletion of gases occur; modified atmosphere (MA) is then a better term. Our experiments also gave information about a) gas exchange mechanisms and b) the influence of headspace composition on plant growth and development. These are prerequisites for the understanding and final control of the headspace composition. Three containers, differing in their gas exchange mechanism, were evaluated. This paper also considered that even under “controlled” culture conditions (container, environment, explant weight, etc.) variations from container to container are registered, probably due to the explant itself.     

Comparison of 12 different containers for dispensing anti-inflammatory drugs.

Twelve containers manufactured by 10 pharmaceutical companies for dispensing anti-inflammatory drugs, 10 of which are currently in use in the United Kingdom, have been compared in 99 patients with arthritis of the hands. Patients were given the containers in random order and were asked to open them, extract the tablets, and close them. Patients were questioned on ease of handling at each stage and were then timed on reopening and closing each container. Finally, the patients were asked which container was the best and which was the worst. There was a wide variation in popularity of containers. One was judged outstanding on almost every attribute, and four were preferred over the others on most attributes. A successful container for arthritic hands is likely to have a sharply angulated or "wing" cap placed on a tall slim base that is also angulated. Flip off tops, tops with long threads requiring many turns, very small containers, and glass were regarded as unfavourable. Manufacturers should take note of these findings and, where necessary, consider redesigning the containers.     

A scheduling problem for a novel container transport system: a case of mobile harbor operation schedule

Mobile Harbor (MH) is a movable floating platform with a container handling system on board so that it can load/discharge containers to/from an anchored container ship in the open sea. As with typical quay crane operation, an efficient schedule for its operation is a key to enhancing its operational productivity. A MH operation scheduling problem is to determine a timed sequence of loading/discharging tasks, assignment of MH units to each task, and their docking position, with an objective of minimizing the makespan of a series of incoming container ships. A mixed integer programming model is formulated to formally define the problem. As a practical solution method to the problem, this paper proposes a rule-based algorithm and a random key based genetic algorithm (rkGA). Computational results show that the rkGA method produces a better-quality solution than the rule-based method, while requiring longer computation time.     

Added-value of mosquito vector breeding sites from street view images in the risk mapping of dengue incidence in Thailand

Dengue is an emerging vector-borne viral disease across the world. The primary dengue mosquito vectors breed in containers with sufficient water and nutrition. Outdoor containers can be detected from geotagged images using state-of-the-art deep learning methods. In this study, we utilize such container information from street view images in developing a risk mapping model and determine the added value of including container information in predicting dengue risk. We developed seasonal-spatial models in which the target variable dengue incidence was explained using weather and container variable predictors. Linear mixed models with fixed and random effects are employed in our models to account for different characteristics of containers and weather variables. Using data from three provinces of Thailand between 2015 and 2018, the models are developed at the sub-district level resolution to facilitate the development of effective targeted intervention strategies. The performance of the models is evaluated with two baseline models: a classic linear model and a linear mixed model without container information. The performance evaluated with the correlation coefficients, R-squared, and AIC shows the proposed model with the container information outperforms both baseline models in all three provinces. Through sensitivity analysis, we investigate the containers that have a high impact on dengue risk. Our findings indicate that outdoor containers identified from street view images can be a useful data source in building effective dengue risk models and that the resulting models have potential in helping to target container elimination interventions.     

The environmental impact of container pipeline transport compared to road transport. Case study in the Antwerp Harbor region and some general extrapolations

Purpose  

Increasing mobility demands and growing industrial tissue come with a burden for the environment. Inventive solutions are necessary to address this challenge. This paper compares the environmental impact of two alternative container transportation methods over a 25-year time period for a specific trajectory and transport volume in the Antwerp harbor. One is a pipeline concept; the other a road concept to link the Deurganck dock with the right bank in order to transport 2 million containers per year.     

Limitations of relative apparent synapomorphy analysis (RASA) for measuring phylogenetic signal.

In this paper we use hypothetical and empirical data matrices to evaluate the ability of relative apparent synapomorphy analysis (RASA) to measure phylogenetic signal, select outgroups, and identify terminals subject to long-branch attraction. In all cases, except for equal character-state frequencies, RASA indicated extraordinarily high levels of phylogenetic information for hypothetical data matrices that are uninformative regarding relationships among the terminals. Yet, regardless of the number of characters or character-state frequencies, RASA failed to detect phylogenetic signal for hypothetical matrices with strong phylogenetic signal. In our empirical example, RASA indicated increasing phylogenetic signal for matrices for which the strict consensus of the most parsimonious trees is increasingly poorly resolved, clades are increasingly poorly supported, and for which many relationships are in conflict with more widely sampled analyses. RASA is an ineffective approach to identify outgroup terminal(s) with the most plesiomorphic character states for the ingroup. Our hypothetical example demonstrated that RASA preferred outgroup terminals with increasing numbers of convergent character states with ingroup terminals, and rejected the outgroup terminal with all plesiomorphic character states. Our empirical example demonstrated that RASA, in all three cases examined, selected an ingroup terminal, rather than an outgroup terminal, as the best outgroup. In no case was one of the two outgroup terminals even close to being considered the optimal outgroup by RASA. RASA is an ineffective means of identifying problematic long-branch terminals. In our hypothetical example, RASA indicated a terminal as being a problematic long-branch terminal in spite of the terminal being on a zero-length branch and having no possibility of undergoing long-branch attraction with another terminal. RASA also failed to identify actual problematic long-branch terminals that did undergo long-branch attraction, but only after following Lyons-Weiler and Hoelzer's (1997) three-step process to identify and remove terminals subject to long-branch attraction. We conclude that RASA should not be used for any of these purposes.     

Carbon dioxide and ethylene evolution in the culture atmosphere of Magnolia cultured in vitro

Subcultured explants of Magnolia soulangeana Soul, were incubated in tissue culture containers fitted with different types of closures. Type of closure affected the CO₂ concentration, with levels as high as 14% CO₂ being detected. The ethylene concentration increased gradually with time, to as much as 2–3 ppm after 9 weeks. There was a large variation in the composition of the atmosphere within the containers of any one type. The way by which a container was closed influenced exchange of the inner gas phase with the surrounding atmosphere and was important in determining the development of the cultured tissues.     

Crouching Tiger,Hidden Trouble: Urban Sources of Aedes albopictus (Diptera: Culicidae) Refractory to Source-Reduction

Our ultimate objective is to design cost-effective control strategies for Aedes albopictus, the Asian tiger mosquito, an important urban nuisance and disease vector that expanded worldwide during the last 40 years.  We conducted mosquito larval surveys from May through October 2009 in the City of Trenton, New Jersey, USA, while performing intensive monthly source-reduction campaigns that involved removing, emptying, or treating all accessible containers with larvicides and pupicides. We examined patterns of occurrence of Ae. albopictus and Culex pipiens, another urban mosquito, among different container types by comparing observed and expected number of positive containers of each type. Expected use was based on the relative frequency of each container type in the environment. Aedes albopictus larvae and pupae were found significantly more often than expected in medium volumes of water in buckets and plant saucers but were rarely collected in small volumes of water found in trash items such as discarded cups and cans. They were also absent from large volumes of water such as in abandoned swimming pools and catch basins, although we consistently collected Cx. pipiens from those habitats. The frequency of Ae. albopictus in tires indicated rapid and extensive use of these ubiquitous urban containers. Standard larval-based indices did not correlate with adult catches in BG-Sentinel traps, but when based only on Ae. albopictus key containers (buckets, plant saucers, equipment with pockets of water, and tires) they did. Although we found that only 1.2% of the 20,039 water-holding containers examined contained immature Ae. albopictus (5.3% if only key containers were counted), adult populations were still above nuisance action thresholds six times during the 2009 mosquito season. We conclude that in urban New Jersey, effective source reduction for Ae. albopictus control will require scrupulous and repeated cleaning or treatment of everyday use containers and extensive homeowner collaboration.     

The infinitesimal, the deterministic, and the probabilistic: Alternate container inspection policies in invasive species management

Recently, Batabyal and Nijkamp (2005, Stochastic Environmental Research and Risk Assessment 19: 340–347) have shown that in an inspection cycle, regardless of whether the inspection policy choice is made on the basis of an optimization exercise or on the basis of a rule of thumb, the “container policy” dominates the “temporal policy” because the former results in lower long run expected net cost (LRENC) from inspections. In this paper, we continue this line of inquiry and analyze container policies in three scenarios. In the first scenario the time taken to conduct inspections is negligible. In the second scenario, this inspection time is deterministic and in the third scenario this inspection time is stochastic. Specifically, we compare and contrast the LRENC and the optimal container policy in each of these three scenarios.