• The Journal of Korea Robotics Society
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• v.12 no.1
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• pp.86-93
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• 2017

The Expanded Guide Circle (EGC) method has been originally proposed as the guidance navigation method for improving the efficiency of the remote operation using the sensory information. The previous algorithm is, however, concerned only for the omni-directional mobile robot, so it needs to suggest a suitable one for a mobile robot with non-holonomic constraints. The ego-kinematic transform is a method to map points of $R^2$ into the ego-kinematic space which implicitly represents non-holonomic constraints for admissible paths. Thus, robots with non-holonomic constraints in the ego-kinematic space can be considered as "free-flying object". In this paper, we propose an effective obstacle avoidance method for mobile robots with non-holonomic constraints by applying EGC method in the ego-kinematic space using the ego-kinematic transformation. This proposed method shows that it works better for non-holonomic mobile robots such as differential-drive robot than the original one. The simulation results show its effectiveness of performance.

• Journal of the Korean Institute of Navigation
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• v.20 no.2
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• pp.59-76
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• 1996

We have implemented the questionnaire survey to study the structure of consciousness of collegian and the Change of the worth view of the vocation on totally 832 collegians who attended to fisheries and martime colleges. The results were as follows : Most collegian had selected college and department by means of surrounding recommendation and acquired scores without regarding his own aptitude and prospect. The educational aims of the collegian who majored in fisheries and maritime field are to carry out the theory and practise along with emphasizing technical education and human-being education together. Concerning to the status of professor. Most collegian had wanted professor not only who had much comprehensive faculty but also who pointed out than well teaching professor. The collegian who consult their prospect with professor was very rare and they were very negative for the learning majoring in fisheries and maritime field. Because the practice guidance was not accomplished effectively on the account of social aspect, most collegian has avoided jobs relating to fisheries and maritime field. Also, they had selected short term on the job training couse aboard the ship.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.343-351
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• 2015

It is well-known that even the DGNSS (Differential Global Navigation Satellite System) technique in navigation for ground vehicles can only provide several meters of accuracy, such that it is suitable for simple guidance. On the other hand, centimeter to millimeter level accuracy can be obtained by using carrier phase observables in the field of precision geodesy/surveying. In this study, a preliminary study was conducted to apply NRTK (Network-RTK) by NGII (National Geographic Information Institute) to ground vehicle navigation. Onboard GNSS receivers were used for NRTK throughout the country, and the applicability of NRTK on navigation was analyzed based on NRTK surveying results. The analysis shows that the overall ambiguity fixing rate of NRTK is high and is therefore possible to apply it for navigation. In urban areas, however, the fixing rate decreases sharply, therefore, it needs to employ a method to minimize the effect of the float solutions, which can reach up to 10 meters. It is still feasible to obtain a centimeter level of accuracy in some area using NRTK under certain conditions. But, the ambiguity fixing rate of FKP falls down to 55% for high speed vehicles, and so the surveying accuracy should be determined by considering various factors of surveying environments. In addition, it is difficult to fix ambiguities using single-frequency GPS receivers. Finally, several suspicious NRTK(FKP) connection problems occurred during atmospheric disturbances (phase two or up), which should be investigated further in upcoming research.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.114-120
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• 2013

Recently, navigation systems based on wireless communication have been applied to the internal structures such as building or ship. If a stable azimuth information is obtained, these systems can effectively guide the direction of the user's progress through the information and then can improve the performance of guidance. Since conventional method which has acquired an azimuth information using geomagnetic and acceleration sensor(azimuth sensor hereafter) is sensitive to the effects of the magnetic field, it has unstable error range according to the surrounding environment. In order to improve these problems, this paper presents a new relative azimuth estimation algorithm using the displacement of a mobile node and its rotation angle based on Wireless communication. For the performance assessment of the proposed algorithm, experiments using rotating arm are performed and the results are confirmed that the proposed system can estimate the relative azimuth without using additional sensors.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.243-251
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• 2020

This study is intended to verify the efficiency of the information system by using the navigation application in case of fire. In the demonstration scenario simulation, it was assumed that a fire occurred 6th floor in Korea Institute of Industrial Design Promotion located in C city, K province. Eighty juniors students from K University's department of paramedics of science participated. As a result of the experiment, the demonstration simulation using the navigation application showed that the evacuation time was faster than the case of evacuation guidance in a fire situation. The need for a fire prevention system and fire prevention awareness before and after the implementation of the demonstration scenario simulation increased the need for a fire prevention system and fire prevention awareness score after the experiment.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.69-78
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• 1999

The attitude determination system is indispensable for navigation, guidance and control tasks. In order to construct this system some special products that use dual frequencies or have on receiver engine with multiple antennas are used. But they are so expensive. Thus there are still strong requirements for the conventional low cost single frequency off-the-shelf receiver. This paper will propose a new technique to resolve integer ambiguity with single frequency GPS receiver and will show the problems of the attitude applications in which low cost receiver are being used. Also, based on this new technique precise attitude determination is presented.

• Korean Journal of Computational Design and Engineering
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• v.13 no.3
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• pp.227-234
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• 2008

The number of marine accidents have been decreased since various equipments for navigation control have been introduced to the marine vessels. However, disastrous marine accidents such as ship collisions are occurred more frequently. Therefore, IMO(International Maritime Organization) is enforcing the design requirement of structural strength for marine vessel. Also EU countries are developing new design methodologies and design tools to suggest the design guidance which can minimize the damage of commercial vessels in case of marine collision accidents. In this study, an integrated design system for the safety assessment has been presented to enhance the safety of damaged ships in marine collision accidents. The architecture of system is described by use-cases and IDEF functional analysis. Then an integrated system for safety assessment of damaged ship which is considering both damage stability and structural safety has been developed to support the ship design in early stage.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.474-479
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• 1993

A study about two-dimensional pursuit-evasion dynamic games is presented and discussed. A pursuer tries to intercept an evader by a strategy based on proportional navigation guidance, while the evader tries to maximize a miss distance by the optimal control. The study is applied to a ball game and an air-combat game. The results show the same features exist in both games, therefore the study will be able to apply for general two dimensional dynamic games. In the ball game, the study is extended to cases where a goal exists, while in the air-combat game, some three-dimensional problems are solved and the results are also shown.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.2
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• pp.9-15
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• 2014

'Visual segment surface' means a surface that extends from the missed approach point of non precision approaches (or the decision altitude location for approaches with vertical guidance and precision approaches) to the threshold to facilitate the identification of and protection from obstacles in this visual segment of the approach. Validation is the necessary final quality assurance step in the procedure design process, prior to publication. The purpose of validation is the verification of all obstacle and navigation data, and assessment of flyability of the procedure. This paper shows how to apply the protection for the visual segment of the approach procedure, and the results of the validation for visual segment surface conducted at an airport.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3023-3032
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• 1997

This study examined individual differences in navigating in hyperspace learning environment where a minimum structure is provided. Using a hypercard stack called "Pearl Harbor", Field Dependent people used guidance more often than those in Field Indepedent; FI achieved scored higher at the end of the study; and FI people had some type of pattern showing from them audit trail when FD people did not show any trail of patterns. Also people with higher visual thinking scores achieved higher scores in hyperspace environment.