• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.801-804
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• 2003

The autopilot system of vessel is proposed to take service safety sorority, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of it is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieving to compensate various nonlinear parameters of vessel and apply it is course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship are nonlinear, which affect various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcome nonlinear parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2321-2330
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• 2015

A variety of studies for indoor positioning are now being in progress due to the limit of GPS that becomes obsolete in the room. However, most of them are based on private wireless networks and the situation is difficult to commercialize them since they are expensive in terms of installation and maintenance costs, non-real-time, and not accurate. This paper applies the mark recognition algorithm used in existing augmented reality applications to the indoor vehicle positioning application. It installs floor marks on the ground, performs the perspective transformation on it and decodes the internal data of the mark and, as a result, it obtains an absolute coordinate. Through the geometric analysis, it obtains current position (relative coordinates) of a vehicle away from the mark and the heading direction of the vehicle. The experiment results show that when installing the marks every 5 meter, an error under about 30 cm occurred. In addition, it is also shown that the mark recognition rate is 43.2% of 20 frames per second at the vehicle speed of 20km/h. Thus, it is thought that this idea is commercially valuable.

• Journal of the Korean association of regional geographers
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• v.11 no.3
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• pp.351-366
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• 2005

In Joseon dynasty, national roads for mainly official trips, were designed to connect capital directly to each county seat or eupchi, and militarily strategic points. The entrance of county seat where national road reach to (sometimes there has been a gate of fortress), regarded as main entrance of the county seat Also the direction county office or gwan-a ordinally heads was regarded as main entrance. Therefore, starting point of national road from county seat was not always heading for capital, but south because most of county offices head south. Nevertheless, actual traffic often ignore such a symbolic rule, and formed another practical routes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1094-1104
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• 2010

In the previous studies, the validation of numerical codes has been conducted based on the qualitative comparison of predicted ice shapes with experiments, which poses a significant limit on the systematic analysis of ice shapes due to the variation of meteorological conditions. In response to this, the numerical code has been quantitatively validated against available experiment for the ice accretion on cylinders and airfoils in the present study. Ice shapes accumulated on the bodies are systematically investigated with respect to various icing parameters. To this end, maximum thickness, heading direction and ice thickness are quantified and expressed in the polar coordinate system for the comparison with other numerical results. By applying the quantitative analysis, similar shapes are intuitively distinguished. The developed numerical code underestimates the ice accretion area and the ice thickness of lower surface. In order to improve the accuracy, further accurate aerodynamic solver is required for the water droplet trajectories.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.1-7
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• 2006

This paper presents a new point navigation guidance law which is useful for unmanned helicopters. Predicting the future position, the guidance law generates velocity and heading commands, which are used as input to autopilot. This method differs from conventional guidance law in that it reorients the direction of flight velocity vector directly, not by bank angle indirectly. For flight tests, we have developed a flight control system for a R/C helicopters. The system consists of a flight control computer, navigation sensors, and a ground station The results of the test show that the proposed law guides a unmanned helicopter along a line path within a given area. In the future, we are planning to extend the guidance law to the mission of path following. i.e., waypoint navigation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1509-1513
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• 2003

The autopilot system of vessel is proposed to take service safety and security, to elevate service efficiency, to decrease labor and to improve working environment. Ultimate purpose of the proposed system is to minimize the number of crew by guaranteeing economical efficiency of shipping service. Recently, the research is being achieved to compensate various nonlinear parameters of vessel and apply it to course keeping control, track keeping control, roll-rudder stabilization, dynamic ship positioning and automatic mooring control etc. using optimizing control technique. Relation between rudder angle controlled by steering machine of vessel and ship-heading angle, and load condition of ship is nonlinear, which affects various parameters of shipping service. The speed and direction of waves, velocity and quantity of wind, which also cause the non-linearity of it. Therefore the autopilot system of ship requires the robust control algorithm can overcome various non-linearity. On this paper, we design the autopilot system of ship, which overcomes nonlinear Parameters and disturbance of it using Fuzzy Algorithm, evaluate the proposed algorithm and its excellence through simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.2
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• pp.129-136
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• 2014

Target-tracking systems are important for carrying out effective surveillance missions using mobile surveillance robots. In this paper, we propose a target-tracking algorithm using camera image data for a three-axis mobile surveillance robot and carry out an actual hardware test for verifying the proposed algorithm. The heading direction vector of a camera system is deduced from the position error between the viewfinder center and the object center in a camera image. The position error is obtained using the CAMShift(Continuously Adaptive Mean Shift) algorithm, an image processing technique. The performance test of an actual three-axis mobile surveillance robot was carried out for verifying the proposed target-tracking algorithm in a real environment.

• Korean Journal of Remote Sensing
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• v.17 no.1
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• pp.45-56
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• 2001

To acquire seabed information, the mosaic images of the seabed were generated using Side Scan Sonar. Short time energy function which is needed for slant range correction is proposed to get the height of Tow-Fish to the reflected acoustic amplitudes of each ping, and that leads to a mosaic image without water column. While generating mosaic image, maximum value, last value and average value are used for the measure of a pixel in the mosaic image and 3-D information was kept by using acoustic amplitudes which were heading for specific direction. As a generating method of mosaic image, low resolution mosaic image which is over 1m/pixel resolution was generated for whole survey area first, and then high resolution mosaic image which is generated under 0.1m/pixel resolution was generated for the selected area. Rocks, ripple mark, sand wave, tidal flat and artificial fish reef are found in the mosaic image.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.521-534
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• 2021

Purpose: In this paper, we propose an indoor positioning scheme based on pedestrian dead reckoning using inertial measurement unit. By minimizing the effects of the orientation error of smart-phone, the more accurate estimation for the direction, the step count, and the stride can be achieved. Method: The effectiveness and the performance of the proposed scheme is evaluated by experiments, and it is compared with the conventional scheme in the same conditions. Result: The results showed that the positioning error of the proposed scheme was 0.76m, while that of the conventional scheme was 1.84m. Conclusion: Sine most people carry his/her own smart-phone, the proposed scheme can be helpful to recognize where he/she was and was heading when the fast evacuation is needed in indoors.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.1-11
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• 2021

Document page segmentation is an important step in building a quality optical character recognition module. The study examined already existing work on the topic of page segmentation and focused on the development of a segmentation model that has greater functional significance for application in an organization, as well as broad capabilities for managing the quality of the model. The main problems of document segmentation were highlighted, which include a complex background of intersecting objects. As classes for detection, not only classic text, table and figure were selected, but also additional types, such as signature, logo and table without borders (or with partially missing borders). This made it possible to pose a non-trivial task of detecting non-standard document elements. The authors compared existing neural network architectures for object detection based on published research data. The most suitable architecture was RetinaNet. To ensure the possibility of quality control of the model, a method based on neural network modeling using the RetinaNet architecture is proposed. During the study, several models were built, the quality of which was assessed on the test sample using the Mean average Precision metric. The best result among the constructed algorithms was shown by a model that includes four neural networks: the focus of the first neural network on detecting tables and tables without borders, the second - seals and signatures, the third - pictures and logos, and the fourth - text. As a result of the analysis, it was revealed that the approach based on four neural networks showed the best results in accordance with the objectives of the study on the test sample in the context of most classes of detection. The method proposed in the article can be used to recognize other objects. A promising direction in which the analysis can be continued is the segmentation of tables; the areas of the table that differ in function will act as classes: heading, cell with a name, cell with data, empty cell.