• Structural Engineering and Mechanics
• /
• v.44 no.3
• /
• pp.289-303
• /
• 2012

Existing plane stress solutions for thin plates and disks have shown several qualitative features which are difficult to handle with the use of commercial numerical codes (non-existence of solutions, singular solutions, rapid growth of the plastic zone with a loading parameter). In order to understand the effect of temperature and pressure-dependency of the yield criterion on some of such features as well as on the distribution of residual stresses and strains, a semi-analytic solution for a thin hollow disk fixed to a rigid container and subject to thermal loading and subsequent unloading is derived. The material model is elastic-perfectly/plastic. The Drucker-Prager pressure-dependent yield criterion and the equation of incompressibity for plastic strains are adopted. The distribution of residual stresses and strains is illustrated for a wide range of the parameter which controls pressure-dependency of the yield criterion.

• Journal of Navigation and Port Research
• /
• v.29 no.8 s.104
• /
• pp.747-753
• /
• 2005

In this paper, as an anti-sway control strategy of container cranes, we investigate a variable structure control in which the moving load follows a given trajectory, whereas both the trolley and hoist controllers achieve their positioning problems. It is crucial, in an automated container terminal, that collisions should be avoided during the transference of containers from one place to another. It is also necessary, in the case of a quay crane, to select suitable loading and unloading trajectories of containers, so that possible collisions with surrounding obstacles are avoided. After a brief introduction of the mathematical model, a robust control scheme (i.e., a second-order sliding mode control that guarantees a fast and precise transference and a suppression of the resulted swing) is presented. Despite model uncertainties and unmodeled actuators dynamics, the swing suppression from the given trajectory is obtained by constraining the system motion on suitable sliding surfaces, which include both the desired path and the swing angle. The proposed controller has been tested with a laboratory-size pilot crane. Experimental results are provided.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.05a
• /
• pp.61-62
• /
• 2023

There have been cases where the number of port workers has temporarily decreased due to COVID-19. To prevent the spread of COVID-19, a number of workers were quarantined, resulting in bottlenecks and waiting throughout the port operation process, increasing the congestion of terminals. As a result, problems such as a decrease in terminal operation efficiency occurred. However, it is understood that congestion centered on unloading equipment inside the terminal is not clearly calculated. Terminal congestion is thought to be a key factor directly related to the operational efficiency of the terminal. The congestion calculation method generally used in various fields measures congestion based on image-based data. Due to the nature of the loading and unloading equipment that moves according to the quantitative loading plan, it is unreasonable to apply the existing congestion calculation method. Therefore, this study presented a method of calculating terminal congestion using equipment waiting time and turnaround time, and verified the statistical significance of the congestion calculated using data from Terminal A of Busan Port.

• Journal of Navigation and Port Research
• /
• v.44 no.3
• /
• pp.195-202
• /
• 2020

The production of larger of ships is a survival strategy for global shipping companies to pursue the economics of scale. According to this strategy, to respond to this situation, many containers are loading/unloading simultaneously in the hub port. Additionally, the container terminals are promoting the introduction of automation to expand the terminal facilities and increase efficiency/productivity of the container yards. European ports have introduced automation to address rising labor costs and shortages of labor. Recently, the construction of fully automated container terminals is increasing in the United States and China to resolve problems such as the slow growth of the global economy, the emergence of large ships, air pollution, and safety accidents. Domestic ports are at an early stage compared to the world's advanced container terminals, and countermeasures are being prepared to respond to the changing ports. However, research on the recognition difference analysis that examines the opinions of stakeholders is insufficient. As a result of analyzing the recognition among the groups, it was found that container terminal operators reduced labor costs, improved shipping services for shipping companies, prevented safety accidents for port union labor, and increased service for port authority and government agencies. Thus, to closely examine the perception among the groups, one-way ANOVA was performed, and then the implications were deduced as the basic data for the smooth introduction of automation.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.515-520
• /
• 2002

Automatic Transfer Crane is needed for automation of container terminal. It requires the control capability of exact position for loading/unloading job in yard. But it has the limitation of improvement because it has the operational environmental and its structural problems. It has the positioning errors caused by the deformation of rail, yawing motion of crane, wear of wheel, sliding motion between wheel and rail and so on. This study shows the calibration method of crane position by using the primitivity sensor and calibrating plate fixed on the ground.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.10
• /
• pp.1999-2007
• /
• 2007

This article describes advanced clover algorithm for effective loading and unloading of containers using stackers position data in a yard. The job scheduling must rely on job assign of stackers and position data processing to dynamically allocate stackers, and maintain multiple job processing, all based on task requirements. A stacker tracking using GPS and GIS is an essential capability and is used as yard loading and unloading process improvement for yard management. After estimating position of stackers in a yard the raper describes advanced clover algorithm and other techniques for monitoring loading and unloading of individual containers as well as combinatorial stacker load balancing problems such as estimating load of each stackers. Results from simulations and experimental implementations have demonstrated that the suggested approaches are efficient in stacker management.

• Journal of Korea Port Economic Association
• /
• v.28 no.4
• /
• pp.275-298
• /
• 2012

Terminal operators have provided special services such as loading, discharging, stowage of cargo to the owner, and carriers of the sea, which contribute the domestic and international logistics. For smooth flow of logistics, container terminal should reserve spaces for inbound and outbound logistics. However, if it is unable to provide the spaces, which can be caused by labour strikes or terminal lockouts and so on, national logistic system and financial management of terminal operators can be seriously affected. In order to minimize these kinds of problems, terminal operators impose high rate of charges ("overstorage charge") to the accumulated cargoes and/or containers, which are stipulated in terminal service agreement. Nevertheless, if there is no terminal service agreement with an owner of cargo and/or container, any kind of charge can cause legal problems (conflict ??) between the cargo and terminal operator. In this regard, I would like to study on the definition of overstorage charge and the legal issue of it based on the Busan district court's judgment. In particular, I will propose a special right of commercial lien and public auction for terminal operators to settle accumulated cargoes in container terminal.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.3268-3277
• /
• 2011

Uiwang ICD, which is the only inland container depot in the capital area, is equipped with modern facilities, and loading and unloading equipment, and can handle 1,000,000 TEU annually.It has many advantages such as advantageous conditions of location, the role of foothold for distribution transportation in the capital area, so it plays an important role of vitalizing the railroad transport. However, Uiwang ICD has reached the limit in the vitalization of railroad transport of containerized cargo due to the current problems in facilities and operations. This research analyzed the Uiwang ICD's problems by dividing them into facilities problems and operational problems, and presented short-term and medium and long-term improvement measures with the year 2023 when the private use permission expires as the basic year. However, the vitalization of railroad transport of Uiwang ICD can be attained only when it has support and cooperation from the government, Uiwang-si, Korea Rail Network Authority, and other related organizations together with efforts of Korea Railroad Corporation, and occupant companies. Such improvement measures for Uiwang ICD are expected to contribute to establishing combined transport system and forming efficient railroad distribution infrastructures and vitalizing railroad distribution, and also contribute to the government's low-carbon green growth policy by building environment-friendly transport system.

• IE interfaces
• /
• v.24 no.4
• /
• pp.281-294
• /
• 2011

This paper considers the rail crane scheduling problem which is defined as determining the sequence of loading/unloading container on/from a freight train. The objective is to minimize the weighted sum of the range of order completion time and makespan. The range of order completion time implies the difference between the maximum of completion time and minimum of start time of each customer order consisting of jobs. Makespan refers to the time when all the jobs are completed. In a rail freight terminal, logistics firms as a customer wish to reduce the range of their order completion time. To develop a methodology for the crane scheduling, we formulate the problem as a mixed integer program and develop three metaheuristics, namely, genetic algorithm, simulated annealing, and tabu search. To validate the effectiveness of heuristic algorithms, computational experiments are done based on a set of real life data. Results of the experiments show that heuristic algorithms give good solutions for small-size and large-size problems in terms of solution quality and computation time.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.2772-2774
• /
• 2000

According to the development of marine transportation business and the modernization and over sizing of vessel transportation equipment. shipping equipment used in the terminal are getting more atomized and speedier. thus the efficiency of shipping and discharging depends upon the degree of practice of terminal operating manpower. It means that cultivation of experts in this field is essentially needed and it is becoming a serious problem to guarantee the training programs to provide high-class. high-skilled manpower. The best result can be expected when we use the real equipment for training purposes. but it will cause many difficulties such as budget problem. To overcome this situation. we developed the Virtual Container Crane Simulator(VCCS System) which enables the operator to learn the operation of the equipment as well as safety problems within a short time. VCCS system begins with establishing the direction of operation by setting the appropriate motions for each step. and then it instructs the basic operation. It enhances the driver's ability to cope with accidents during operation and completes and completes the mastery of operating techniques with The repetition of practice.