• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.205-208
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• 2015

Large vessels are currently operating by using an ECDIS, a system enabling automatic navigation and checking marine conditions. In the past, the ECDIS was used for vessels but in these days, it has been used as a method for collecting and verifying marine information, etc. from land by using a computer, instead of taking a boat out. The ECDIS on sale is generally used by companies which operate marine workers. However, this system has caused inconvenience to marine workers, in terms of tasks, services, or operations. Marine workers move out to the sea after checking the status of the system at the office. Due to the weather such as waves and winds, marine devices are not often found on the relevant coordinates. In such a case, the workers onerously need to come back to the land and track the marine devices again. In order to solve such a problem, this thesis purposes to develop a system which can check the locations of marine devices and verify a marine chart even on the sea by using a mobile. The proposed system can integrate and support a variety of protocols of relevant devices in the system itself and check data via mobile through the data transmission and streaming functions.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3236-3246
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• 2000

XML is a meta-language as SGML and also can be xonsructed as an Internet versionof simplified SGML being used in confunction with XLL. Xpointer and XSL. Also W3C established DTDless Well-Formed XML document to use XML document on the Web. But it isnt offered system that consists of browsing, link and DTD generating facihty, and efficiently processes DTDless Well-Formed XML document. This paper studies on an implementation and design of system to process DTDless Well-Formed XML document on the client-side. This system consists of Well-Formed XML viewer displaying Well-Formed XML documet, XLL Processor processing Xll and Auto DTD generator constructing automatically DTDs based on multiple documents of the same class. This study focuses on automatic DTD generation during hyperlink navigation and an implementation of extended links based on XLL and Xpointer. ID and Xpointer location address are used as the address mode in the links. As a result of implement of this system, it conforms to validationof extended link facihties, extracts DTD from Well-Fromed XML Documents including same root element at the same class and constructs generalized DTD.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1425-1434
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• 2021

Continuous and periodic data acquisition must be preceded to maintain and manage the river facilities effectively. Adapting the existing general facilities methods, which include river surveying methods such as terrestrial laser scanners, total stations, and Global Navigation Satellite System (GNSS), has limitation in terms of its costs, manpower, and times to acquire spatial information since the river facilities are distributed across the wide and long area. On the other hand, the Mobile Mapping System (MMS) has comparative advantage in acquiring the data of river facilities since it constructs three-dimensional spatial information while moving. By using the MMS, 184,646,009 points could be attained for Anyang stream with a length of 4 kilometers only in 20 minutes. Levee points were divided at intervals of 10 meters so that about 378 levee cross sections were generated. In addition, the waterside maximum and average slope could be automatically calculated by separating slope plane form levee point cloud, and the accuracy of RMSE was confirmed by comparing with manually calculated slope. The reference slope was calculated manually by plotting point cloud of levee slope plane and selecting two points that use location information when calculating the slope. Also, as a result of comparing the water side slope with slope standard in basic river plan for Anyang stream, it is confirmed that inspecting the river facilities with the MMS point cloud is highly recommended than the existing river survey.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.483-491
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• 2021

The identification of regional collision risks in water areas is significant for the safety of navigation. This paper introduces a new method of collision risk assessment that incorporates a clustering method based on the distance factor - hierarchical clustering - and uses real-time data in case of several surrounding vessels, group methodology and preliminary assessment to classify vessels and evaluate the basis of collision risk evaluation (called HCAAP processing). The vessels are clustered using the hierarchical program to obtain clusters of encounter vessels and are combined with the preliminary assessment to filter relatively safe vessels. Subsequently, the distance at the closest point of approach (DCPA) and time to the closest point of approach (TCPA) between encounter vessels within each cluster are calculated to obtain the relation and comparison with the collision risk index (CRI). The mathematical relationship of CRI for each cluster of encounter vessels with DCPA and TCPA is constructed using a negative exponential function. Operators can easily evaluate the safety of all vessels navigating in the defined area using the calculated CRI. Therefore, this framework can improve the safety and security of vessel traffic transportation and reduce the loss of life and property. To illustrate the effectiveness of the framework proposed, an experimental case study was conducted within the coastal waters of Mokpo, Korea. The results demonstrated that the framework was effective and efficient in detecting and ranking collision risk indexes between encounter vessels within each cluster, which allowed an automatic risk prioritization of encounter vessels for further investigation by operators.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.462-469
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• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1135-1147
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• 2021

In order to geometrically correct high-resolution satellite imagery, the sensor modeling process that restores the geometric relationship between the satellite sensor and the ground surface at the image acquisition time is required. In general, high-resolution satellites provide RPC (Rational Polynomial Coefficient) information, but the vendor-provided RPC includes geometric distortion caused by the position and orientation of the satellite sensor. GCP (Ground Control Point) is generally used to correct the RPC errors. The representative method of acquiring GCP is field survey to obtain accurate ground coordinates. However, it is difficult to find the GCP in the satellite image due to the quality of the image, land cover change, relief displacement, etc. By using image maps acquired from various sensors as reference data, it is possible to automate the collection of GCP through the image matching algorithm. In this study, the RPC of KOMPSAT-3A satellite image was corrected through the extracted matching point using the UAV (Unmanned Aerial Vehichle) imagery. We propose a pre-porocessing method for the extraction of matching points between the UAV imagery and KOMPSAT-3A satellite image. To this end, the characteristics of matching points extracted by independently applying the SURF (Speeded-Up Robust Features) and the phase correlation, which are representative feature-based matching method and area-based matching method, respectively, were compared. The RPC adjustment parameters were calculated using the matching points extracted through each algorithm. In order to verify the performance and usability of the proposed method, it was compared with the GCP-based RPC correction result. The GCP-based method showed an improvement of correction accuracy by 2.14 pixels for the sample and 5.43 pixelsfor the line compared to the vendor-provided RPC. In the proposed method using SURF and phase correlation methods, the accuracy of sample was improved by 0.83 pixels and 1.49 pixels, and that of line wasimproved by 4.81 pixels and 5.19 pixels, respectively, compared to the vendor-provided RPC. Through the experimental results, the proposed method using the UAV imagery presented the possibility as an alternative to the GCP-based method for the RPC correction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.508-516
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• 2010

An autonomous and automatic home mess-cleanup robot is newly developed in this paper. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot (McBot) to completely overcome this problem. The robot needs the capability for agile navigation and a novel manipulation system for mess-cleanup. The autonomous navigational system has to be controlled for the full scanning of the living room and for the precise tracking of the desired path. It must be also be able to recognize the absolute position and orientation of itself and to distinguish the messed object that is to be cleaned up from obstacles that should merely be avoided. The manipulator, which is not needed in a vacuum-cleaning robot, has the functions of distinguishing the large trash that is to be cleaned from the messed objects that are to be arranged. It needs to use its discretion with regard to the form of the messed objects and to properly carry these objects to the destination. In particular, in this paper, we describe our approach for achieving accurate localization using RFID for home mess-cleanup robots. Finally, the effectiveness of the developed McBot is confirmed through live tests of the mess-cleanup task.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.45-53
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• 2015

These days Container Terminals are focusing on increasing the quantity of containers and shipping lines choose Terminals by referring to the key elements of a terminal to perform the overall operation the fastest such as the location of the terminal, discharging ability, keeping environment, and other elements related to shipping in general. Container terminal is able to offer On-Dock service has become an important factor for shipping lines to choose that terminal. In this paper, we propose an algorithm for On-Dock system work algorithm, the algorithm Empty container exports, Full Container algorithm and The aim of our study focus on both container's gate out time and search for the effective terminal operation which is using the general On-Dock system through several algorithm like container batch priority, gate in and out job priority and empty container yard equipment allocation rule based on the automatic allocation method and manual allocation scheme for container. Gathering these information, it gives the priority and yard location of gate-out containers to control. That is, by selecting an optimum algorithm container, container terminals Empty reduces the container taken out time, it is possible to minimize unnecessary re-handling of the yard container can be enhanced with respect to the efficiency of the equipment. Operations and operating results of the Non On-Dock and On-Dock system is operated by the out work operations (scenarios) forms that are operating in the real Gwangyang Container Terminal derived results. Gwangyang Container terminal and apply the On-Dock system, Non On-Dock can be taken out this time, about 5 minutes more quickly when applying the system. when managing export orders for berths where On-Dock service is needed, ball containers are allocated and for import cargoes, D/O is managed and after carryout, return management, container damage, cleaning, fixing and controlling services are supported hence the berth service can be strengthened and container terminal business can grow.