Design of liquid container handles in accordance with user preferences

In this study, a prototype liquid container combined with auxiliary handles was designed to increase the safety of manual handling and to protect users of these containers from hand contamination. A Likert summated rating method as well as a pairwise ranking test was applied to evaluate the user preferences for handles provided for the container under the conditions of different shapes and positions. The results show that the participants preferred perpendicular orientation of the handle on the top of the liquid container while carrying the containers and the crosswise position of the handle at the side of the container while pouring the liquid. In order to satisfy both conditions, the container needs to be designed with handles in perpendicular as well as crosswise positions for selective application. A prototype liquid container with provided auxiliary handles was developed based on the results of the evaluation. It is recommended that a liquid container provides extra handles to reduce musculoskeletal stress and in turn increase user satisfaction.     

Design of liquid container handles in accordance with user preferences

In this study, a prototype liquid container combined with auxiliary handles was designed to increase the safety of manual handling and to protect users of these containers from hand contamination. A Likert summated rating method as well as a pairwise ranking test was applied to evaluate the user preferences for handles provided for the container under the conditions of different shapes and positions. The results show that the participants preferred perpendicular orientation of the handle on the top of the liquid container while carrying the containers and the crosswise position of the handle at the side of the container while pouring the liquid. In order to satisfy both conditions, the container needs to be designed with handles in perpendicular as well as crosswise positions for selective application. A prototype liquid container with provided auxiliary handles was developed based on the results of the evaluation. It is recommended that a liquid container provides extra handles to reduce musculoskeletal stress and in turn increase user satisfaction.     

A routing algorithm for a single transfer crane to load export containers onto a containership

It is discussed how to route transfer crane during loading operation of export containers in port container terminal. We determine the number of containers which transfer crane picks up at each yard-bay as well as the sequence of yard-bays which transfer crane visits during the tour. The objective is to minimize the total container handling time of the transfer crane including the set-up time at each yard-bay and the travel time between consecutive yard-bays. This routing problem is formulated as an integer programming. An efficient optimizing algorithm is also developed for the crane routing problem.     

Event-driven receding horizon control for energy-efficient container handling

The performance of container terminals needs to be improved to adapt the growth of containers while maintaining sustainability. This paper provides a methodology for determining the trajectory of interacting machines that transport containers between the quayside area and the stacking area in an automated container terminal. The behaviors of the interacting machines are modeled as a combination of discrete-event dynamics and continuous-time dynamics. An event-driven receding horizon controller (RHC) is proposed for achieving energy efficient container handling. The underlying control problems are hereby formulated as a collection of small optimization problems that are solved in a receding horizon way. Simulation studies illustrate that energy consumption of container handling can indeed be reduced by the proposed methodology. Moreover, an assessment is made of performance of the proposed RHC controller under different types of uncertainties.     

Computerized container-ship load planning: A methodology and evaluation

A heuristic is developed to plan loads for containerized cargo ships. It is designed to serve a port which uses gantry cranes (transtainers) and trucks to handle containers. The model recognizes constraints on ship stability, placing containers in a bay with the proper length, limits on stack height in under-deck bays, limits on stack weight in on-deck bays, refrigerated containers, and the need for support under a container. Provisions are made for the operator to handle overstowage of cargo for different ports and placement of oversize cargo. The model uses minimization of transtainer movement time and minimization of rehandles in the yard as an objective. The heuristic uses strategies for container placement similar to those used in manual load planning. A test of two ships and four voyages at the Port of Portland produced feasible load plans for each voyage. Transtainer movement and rehandling time varied for the four voyages; but on the average, the heuristic reduced a composite material handling measure by 4.8%.     

基于改进Canny边缘检测的堆叠货箱分割定位方法

为了提高集装箱卸货的自动化水平,针对集装箱内堆叠货箱难分割定位的问题,提出了一种基于改进Canny边缘检测的堆叠货箱分割定位方法。通过阈值分割和形态学处理进行图像预处理,去除背景干扰,提取堆叠货箱区域图像,基于改进Canny算法对堆叠货箱进行边缘检测,根据堆叠货箱边缘特征进行筛选并基于最小二乘法进行直线拟合,解决边缘线条不连续和虚假边缘问题,对边缘进行区域化处理,以此将堆叠货箱分割成独立的货箱区域,提取每个独立货箱的最小外接矩形,得到货箱中心点的位置信息。实验结果表明,该方法对堆叠货箱有很好的分割效果,定位精度小于5 mm,满足定位精度要求。     

Application of a mixed fuzzy decision making and optimization programming model to the empty container allocation

Containerization transportation has been growing fast in the past few decades. International trades have been growing fast since the globalization of world economies intensified in the early 1990s. However, these international trades are typically imbalanced in terms of the numbers of import and export containers. As a result, the relocation of empty containers has become one of the important problems faced by liner shipping companies. In this paper, we consider the empty container allocation problem where we need to determine the optimal volume of empty containers at a port and to reposition empty containers between ports to meet exporters’ demand over time. We formulate this empty container allocation problem as a two-stage model: in stage one, we propose a fuzzy backorder quantity inventory decision making model for determining the optimal quantity of empty container at a port; whereas in stage two, an optimization mathematical programming network model is proposed for determining the optimal number of empty containers to be allocated between ports. The parameters such as the cost of loading container, cost of unloading container, leasing cost of empty container, cost of storing container, supplies, demands and ship capacities for empty containers are considered in this model. By taking advantages of the fuzzy decision making and the network structure, we show how a mixed fuzzy decision making and optimization programming model can be applied to solve the empty container allocation problem. The utilization of the proposed model is demonstrated with a case of trans-Pacific liner route in the real world. Six major container ports on the trans-Pacific route are considered in the case study, including the Port of Kaohsiung, the Port of Hong Kong, the Port of Keelung, the Port of Kobe, the Port of Yokohama and the Port of Los Angles. The results show that the proposed mixed fuzzy decision making and optimization programming model can be used to solve the empty container allocation problem well.     

Effect of a redesigned two-wheeled container for refuse collecting on mechanical loading of low back and shoulders

The objective of this study was to compare the mechanical and perceived workload when working with a redesigned two-wheeled container and working with a standard two-wheeled container for refuse collecting. The three changes in the design of the container were a displacement of the position of the centre of mass in the direction of the axis of the wheels, a slight increase in the height of the handle and a slight increase in the horizontal distance between the handle and the wheel-axis, and an increase in the diameter of the wheels. The volume of the container remained 0.240 m³. Nine refuse collectors performed some of their most frequent daily activities with both types of containers in the laboratory. Kinematics and exerted hand forces were assessed as input for detailed 3D biomechanical models of the low back and shoulder to estimate net moments at the low back and shoulders, compressive forces at the low back and contact forces at the glenohumeral joint. Also, the refuse collectors rated the ease of handling the two-wheeled containers on a five point scale. The use of the redesigned container resulted in a decrease of the exerted hand forces of 27%, decreases in the net moments at the low back and shoulders of 8% and 20%, respectively, and a decrease of 32% of the contact force at the glenohumeral joint when compared to the standard container. However, pulling an empty redesigned container on to the pavement resulted in an increase of the shoulder moment of more than 100%. No differences between container types were found for the compressive forces at the low back. Pushing and pulling with the redesigned container was rated as easier than pushing and pulling with the standard container. No differences in subjective ratings were found for the tasks of turning the container or pulling an empty container onto the pavement. It is concluded that, provided that empty containers are placed back onto the pavement as infrequently as possible, the introduction of the redesigned container could result in a reduction of the low back and shoulder load for refuse collectors.     

一种基于Cascade R-CNN的电子器件容器质检方法

电子器件容器生产是一种对安全性、高效性、完整性要求极高的过程,是各大企业必须要关注的问题。但是在实际的生产封装过程中,容器上的污渍、容器内的异物,外观的异常不可避免地出现,这些问题亟待解决。目前解决这些问题主要的检测方法还是人工检测和传统的机器视觉的方式,人工检测方式的缺点在于准确率高而效率低,传统机器视觉检测方式是效率高而准确率低,都难以满足高速自动化生产线要求。因此,本文提出一种基于Cascade R-CNN的电子器件容器质检方法,针对实际过程中的容器数据定向改进网络,加入Focal Loss检测难以区分的样本,使用可变形卷积更高效地提取特征,以多尺度训练方式训练强鲁棒性的模型,用于电子器件容器的多类别检测问题。实验结果表明提出的改进的基于Cascade R-CNN的电子器件容器质检模型具有高准确率和强鲁棒性。     

Integrated intelligent techniques for remarshaling and berthing in maritime terminals

Maritime container terminals are facilities where cargo containers are transshipped between ships or between ships and land vehicles (trucks or trains). These terminals involve a large number of complex and combinatorial problems. Two important problems are the container stacking problem and the berth allocation problem. Both problems are generally managed and solved independently but there exist a relationship that must be taken into account to optimize the whole process. The terminal operator normally demands all containers bound for an incoming vessel to be ready in the terminal before its arrival. Similarly, customers (i.e., vessel owners) expect prompt berthing of their vessels upon arrival. This is particularly important for vessels from priority customers who may have been guaranteed berth-on-arrival service in their contract with the terminal operator. To this end, both problems must be interrelated.In this paper, a set of artificial intelligence based-techniques for solving both problems is presented. We develop a planning technique for solving the container stacking problem and a set of optimized allocation algorithms for solving the berth allocation problem independently. Finally we have developed an architecture to solve both problems in an integrated way. Thus, an algorithm for solving the berth allocation problem generates an optimized order of vessels to be served meanwhile our container stacking problem heuristics calculate the minimum number of reshuffles needed to allocate the containers in the appropriate place for the obtained ordering of vessels. Thus combined optimal solutions can be calculated and the terminal operator could decide which solution is more appropriate in each case. These techniques will minimize disruptions and facilitate planning in container terminals.     

基于组件模型分析的组件容器产品线体系结构

组件容器为组件提供部署和运行环境,是基于组件分布式应用开发的核心.近年来分布式组件的多样化和快速演化对组件容器的开发方法提出了挑战.产品线工程是基于公共的核心资产开发特定领域内软件产品系列的软件工程方法,产品线体系结构是其中最重要的部分.进行组件容器产品线体系结构的研究能够提高组件容器的结构复用性,获得更高的生产效率和质量.由于组件模型是组件容器设计的基础,在领域分析阶段引入组件模型分析,提出了组件模型分析框架,通过组件模型元素到领域需求元素的映射,建立组件容器领域模型.提出了组件容器设计的基本原则,并根据变化性封装原则,提出了组件容器产品线体系结构PLACE,通过引入可选属性、模块层次结构和决策模型,实现组件容器的领域需求.PLACE产品线体系结构已在网驰平台的多个组件容器设计中得到应用.     

Handle positions in a holding task as a function of task height

Six handle positions in a two-handed container holding task were tested with the container at floor, waist and shoulder heights. Fifteen male and fifteen female manual materials handlers participated. Handle-position effects on forces exerted, heart rate and psychophysical indices were large compared with the effect produced by a 25% change in container weight. As in a previous study (at waist height only) and an industrial survey, handle positions providing both horizontal and vertical stability were better than symmetrical positions. Optimal angles of handle to container changed greatly with task height, giving almost horizontal angles at floor level and almost vertical angles at waist and shoulder level. Implications for the design of handle cutouts on containers are discussed     

Yard crane scheduling problem in a container terminal considering risk caused by uncertainty

In a container terminal, the arriving times and handling volumes of the vessels are uncertain. The arriving times of the external trucks and the number of containers which are needed to be brought into or retrieved from a container terminal by external trucks within a period are also uncertain. Yard crane (YC) scheduling is under uncertainty. This paper addresses a YC scheduling problem with uncertainty of the task groups' arriving times and handling volumes. We do not only optimize the efficiency of YC operations, but also optimize the extra loss caused by uncertainty for reducing risk of adjusting schedule as the result of the task groups' arriving times and handling volumes deviating from their plan. A mathematical model is proposed for optimizing the total delay to the estimated ending time of all task groups without uncertainty and the extra loss under all uncertain scenarios. Furthermore, a GA-based framework combined with three-stage algorithm is proposed to solve the problem. Finally, the proposed mathematical model and approach are validated by numerical experiments.     

Exact and approximate solutions of the container ship stowage problem

This paper deals with a stowage plan for containers in a container ship. Containers on board a container ship are placed in stacks, located in many bays. Since the access to the containers is only from the top of the stack, a common situation is that contianers designated for port J must be unloaded and reloaded at port I (before J) in order to access containers below them, designated for port I. This operation is called “shifting”. A container ship calling many ports, may encounter a large number of shifting operations, some of which can be avoided by efficient stowage planning. In general, the stowage plan must also take into account stability and strength requirements, as well as several other constraints on the placement of containers. In this paper we deal with stowage planning in order to minimize the number of shiftings, without considering stability constraints. First, a 0–1 binary linear programming formulating is presented that can find the optimal solution for stowage in a single rectangular bay of a vessel calling a given number of ports, assuming that the number of constainers to ship is known in advance. This model was successfully implemented using the GAMS software system. It was found, however, that finding the optimal solution using this model is quite limited, because of the large number of binary variables needed for the formulation. For this reason, several alternative heuristic algorithms were developed. The one presented here is based on a “reduced” transportation matrix. Containers with the same source and destination ports are stowed in full stacks as much as possible, and only the remaining containers are allocated by the binary linear programming model. This approach often allows the stowage planning of a much larger number of containers than using the exact formulation.     

A decomposition method to analyze the performance of frame bridge based automated container terminal

This paper studies a new automated container terminal (ACT) system which utilizes multi-storey frame bridges and rail-mounted trolleys to transport containers between the quay and the yard. Different from widely used AGV–ACT systems, the ACT system studied in this paper uses three types of handling machines, which collaborate to transport containers. This study decomposes the container flow in the new ACT system into three queuing sub-networks. Then an iterative method is developed to analyze the operational efficiency of the ACT system. We analyze its transport efficiency by comparing with the widely used AGV-based systems. This study tries to help port operators better understand the relative merits of this new design and decide whether it is applicable in their terminals.     

海铁联运港口混合作业模式下轨道吊与集卡协同调度

在集装箱海铁联运港口中,铁路作业区作为连接铁路运输和水路运输的重要节点,其装卸效率将影响集装箱海铁联运的整体效率。首先,对比分析了“船舶-列车”作业模式和“船舶-堆场-列车”作业模式的特点,并结合海铁联运港口实际作业情况提出了混合作业模式。然后,以轨道吊完工时间最短为目标构建混合整数规划模型,既考虑了班列和船舶的作业时间窗约束,又考虑了轨道吊间干扰和安全距离、轨道吊和集卡接续作业和等待时间等现实约束。针对遗传算法在局部搜索能力方面的不足,将启发式规则与遗传算法相结合设计了求解轨道吊与集卡协同调度问题的混合遗传算法（HGA）,并进行了数值实验。实验结果验证了所提模型和混合算法的有效性。最后通过设计实验分析集装箱数量、岸边箱占比、轨道吊数量和集卡数量对轨道吊完工时间和集卡完工时间的影响,发现同等集装箱数量下岸边箱占比提高时,应通过增加轨道吊数量来有效缩短完工时间。     

An enriched model for the integrated berth allocation and quay crane assignment problem

Given the increasing pressure to improve the efficiency of container terminals, a lot of research efforts have been devoted to optimizing container terminal operations. Most papers deal with either the berth allocation problem (BAP) or the (quay) crane assignment problem (CAP). In the literature on the BAP, handling times are often simplified to be berth dependent or proportional to vessel size, so the CAP can be ignored when scheduling vessels. This is unsatisfactory for real-life applications because the handling time primarily depends on the number of containers to be handled and the number of cranes deployed. Only a limited number of papers deals with the combination of berth allocation and crane assignment. In these papers however, authors often have resorted to algorithmic simplifications that limit the practical use of the models. This paper presents a MILP model for the integrated BAP–CAP taking into account vessel priorities, preferred berthing locations and handling time considerations. The model is used in a hybrid heuristic solution procedure that is validated on real-life data illustrating the potential to support operational and tactical decision-making.     

MicroPort: A general simulation platform for seaport container terminals

Seaport container terminals are essential nodes in sea cargo transportation networks. As such, the operational efficiency of container terminals in handling containers passing through them plays a critical role in a globalized world economy. Many models and algorithms have been developed to address various decision problems in container terminals to help improve operational efficiency. These decision support tools are usually used separately for specific purposes. However, the problems they are trying to tackle are often interrelated. Therefore, in this regard, an evaluation tool which can capture as many operational conditions as possible for different decision problems is necessary. This paper introduces a general simulation platform, named MicroPort, which aims to provide an integrated and flexible modeling system for evaluating the operational capability and efficiency of different designs of seaport container terminals. The software structure of MicroPort comprises three programming layers: (1) the Functions layer; (2) the Applications layer; and (3) the Extensions layer. Different layers are bound by Application Programming Interfaces (APIs). Basic functions built in the Functions layer support the Applications layer in which major operation processes can be modeled by an agent-based method. External modules and decision support tools in the Extensions layer then use APIs to adjust the system to produce suitable simulation models for specific purposes.     

Reverse logistics: simultaneous design of delivery routes and returns strategies

A reverse logistics problem, motivated by blood distribution of the American Red Cross, is examined where containers in which products are delivered from a central processing point to customers (stops) in one period are available for return to the central point in the following period. Any container not picked up in the period following its delivery incurs a penalty cost resulting primarily from operating costs and customer dissatisfaction. The result is a dynamic logistics planning problem where in each delivery period the vehicle dispatcher needs to design a multi-stop vehicle route while determining the container quantities to be picked up at each stop. This research is unique in that route design and pickup strategies are developed simultaneously, where stop volumes are known only probabilistically over a planning horizon. A heuristic procedure is developed for treating the route design-pickup strategy planning problem.     

A simulation analysis for a transtainer-based container handling facility

The efficiency of a marine cargo terminal depends primarily upon a smooth and orderly flow of material during the container loading process. It has been observed that the transtainer operation is the bottleneck in the loading process due to the frequent container rehandles and its speed. Past attempts at improving port operations have concentrated on the computerization of the load planning function and the efficient warehouse of the outbound containers. These attempts have, to some extent, been successful but have not been able to significantly eliminate the unproductive movements of the material handling equipment during the load operation.This study proposes a methodology of utilizing a buffer space as a method to increase the utilization of the material handling equipment and reduce the total container loading time. A stimulation model using a graphics simulation system is developed to compare the proposed methodology with the current practice at the Port of Portland.The results from 96 simulation runs show that the use of a buffer space significantly improves the flow of material during the loading operation, resulting in an average of 4% reduction in the total loading time. The methodology proposed in this study can be evaluated and implemented for any transtainer-based container port operation, and is anticipated to make considerable contribution to the plannig of future container port design.