• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2013.10a
• /
• pp.167-170
• /
• 2013

The objective of this paper is to describe the result of development of collision avoidance supporting system, based on the electronic chart display and information system(ECDIS). In real ship operations, collision accidents happen frequently due to human errors such as the lax vigilance, misinterpretation of international regulations for preventing collisions at sea (COLREGs). We developed a system which will help to avoid these kind of accidents. This system can automatically recognize the risk of collisions, generate the safe alternative routes that comply with COLREGs, and then deliver the results into auto pilot. A virtual simulation assuming progressive collision situations revealed the usefulness of this system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.7
• /
• pp.760-766
• /
• 2014

This paper represents a portable robot for use in the welding process of the double hulls in shipbuilding yards. It has 5 degrees of freedom and 3kg of payload. Its body weight is 17.3 [kg] so that human workers can carry it by hand to the work place. Its body is mainly made of magnesium and aluminum alloys. Since the robot is placed about 25m apart from its controller, EtherCAT is adopted for reliable connection between the robot and controller through a single light cable. RTX real-time kernel and KPA EtherCAT master are used to control the robot on a Windows XP environment. The performance of the developed robot is satisfactory to the requirement in welding tasks of U-type cells in shipbuilding yards.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.6
• /
• pp.893-900
• /
• 2008

The heat exchangers in the ships have been changed from the conventional shell & tube type to the plate type due to some merits as a compactness, a high thermal efficiency and a light-weight. In recent. it is reported that the vacuum phenomena were occurred in the seawater outlet piping of a main central cooler (MCC) on the ships. From the viewpoints of a common sense, the vacuum pressure in the seawater piping is rare event and difficult to be convinced because the seawater is pumped into the piping by a seawater pump with a high discharge head. However, the occurrence of a vacuum pressure in the seawater line of an MCC is real situation and often gives a severe damage to a rubber gasket of an MCC with a plate type heat transfer area. In this study, we analyzed the vacuum pressure in the seawater line of an MCC by using the simpl Bernoulli's equation and found that the vacuum pressure in the seawater line of an MCC is inevitable untill the installation postion of an MCC is not lowered.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.1
• /
• pp.39-43
• /
• 2008

It is generally recognized that monitering of bio-molecules, which are related to the ocean environment, becomes more important. So far, for the detection of the bio-molecules, ocean samples were brought to laboratory to be analyzed using a complicate and expensive measuring system The "ship and dip" method takes a relatively long time to complete a analysis cycle and causes significant errors due to the time difference between the analysis processes. In order to overcome the drawbacks, developments of sensors for the detection of bio-molecules were suggested using nano-technology, such as nano-spintronic device, carbon nano tube device, and nano-semiconductors. The pros and cons of the technology were examined and reinvestigated to overcome the technical problems in the application to real sensors.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.1
• /
• pp.145-151
• /
• 2017

In this paper, we propose the design and implementation of the system that is predicting the failure of ballast water treatment system by analysing its sensor datum and is reserving the most effective service center for sellecting the repair location on the way to the destination port. These data are collected in real time during draining or filling up the sea water from/to the ship, and it is essential to preliminarily repair the equipment showing unstable characteristics by analyzing the normal and abnormal data characteristics. We proposed a software platform for predicting and repairing faults by selecting the most efficient repair center based on this e-Navigation while the vessel is navigating to the next destination port. This system, as announced by the IMO Convention for the Prevention of Marine Pollution in 2017, provides a stable economic impact from stable cargo operation and stable out/in from/to port and marine ecosystem.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.3
• /
• pp.47-53
• /
• 2017

There is a difficulty in preventing drunken driving by enforcing alcohol control on the sea due to the environment of Marine transportation rather than roads. In the previous study, we proposed the algorithm, that was developed to identify the voices changed according to be drunk. Using the developed algorithm, it became possible to know the possibility of drinking by long distance ship operators and crew members. In that method drinking can be measured in real time, no matter how far the distance is, if the interception is through a voice that can be transmitted over a distance, rather than a short distance. When communicating voice using the VTS wireless devices, clipping occurs when that environment is uneven, and the rate of judgment of the possibility of drinking may be lowered. Therefore, in this paper, we proposed an enhanced method to compensate the signal in order to reduce the error rate of the possibility of drinking due to distortion of the speech signal.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.9
• /
• pp.973-980
• /
• 2015

With their wide geographical distribution, unconventional resources are continuously compared against conventional resources, but their development is expanding because TRRs (Technical Recoverable Resources) are similar to conventional resources. In particular, there is active development of unconventional gas resources such as shale gas, tight gas, CBM (coalbed methane) and gas hydrate. However, it is difficult to calculate the material properties of unconventional resources, especially the gas content, with current geophysical logging technology. Additionally, some overseas companies have monopolies on related equipment and materials. Therefore, this study developed a reservoir PCS (Pressure Core Sampler). It can collect core samples without gaseous loss by maintaining high pressure from the moment the core is sampled and record pressure and temperature in real time. Successful performance testing was also carried out for official verification of the manufactured PCS. The reservoir PCS will contribute to the acquisition of geophysical well logging data as well as accurate and reliable cores.

• The Journal of the Korea Contents Association
• /
• v.20 no.2
• /
• pp.561-571
• /
• 2020

Location information service using big data is continuously developing. In terms of navigation, the range of services from map API service to ship navigation information has been expanded, and system application information has been extended to SNS and blog search records for each location. Recently, it is being used as a new industry such as location-based search and advertisement, driverless cars, Internet of Things (IoT) and online to offline (O2O) services. In this study, we propose an information system that enables users to receive information about nearby stores more effectively by using big data when a user moves a specific route. In addition, we have designed this system so that local stores can use this system to effectively promote it at low cost. In particular, we analyzed web-based information in real time to improve the accuracy of information provided to users by complementing the data. Through this system, system users will be able to utilize the information more effectively. Also, from a system perspective, it can be used to create new services by integrating with various web services.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.17 no.1
• /
• pp.41-41
• /
• 1992

In the real world situations that some jobs need be processed only on certain limited machines frequently occur due to the capacity restrictions of machines such as tools fixtures or material handling equipment. In this paper we consider n-job non-preemptive and m parallel machines scheduling problem having two machines group. The objective function is to minimize the sum of earliness and tardiness with different release times and due dates. The problem is formulated as a mixed integer programming problem. The problem is proved to be Np-complete. Thus a heuristic is developed to solve this problem. To illustrate its suitability and efficiency a proposed heuristic is compared with a genetic algorithm and tabu search for a large number of randomly generated test problems in ship engine assembly shop. Through the experimental results it is showed that the proposed algorithm yields good solutions efficiently.

• Journal of Navigation and Port Research
• /
• v.29 no.1 s.97
• /
• pp.83-90
• /
• 2005

Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered around within the block, so that the containers can be loaded onto the ship efficiently. However, if we rearrange the containers without considering the container loading sequence, excessive rehandling work will be required at the time of loading because the containers to be fetched are often stacked under other containers. Therefore, the remarshalling should be done by moving the relevant containers in an appropriate order. This paper presents an efficient heuristic search technique for finding an appropriate container moving order during remarshalling to avoid rehandling at the time of loading. Simulation experiments have shown that the proposed method can generate rehandling-free solutions in real time.