• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.282-286
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• 2011

Recently, a name retrieval function is widely used on navigation systems. In this paper, we propose the new dynamic hashing algorithm for a name retrieval function on it. The proposed dynamic hashing algorithm by constructing an index using the variance information of character is the better than existing methods in terms of storage capacity and retrieval speed. The algorithm proposed in this paper can be useful on systems that have limited resources as well as navigation systems.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.95-101
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• 2013

The paper investigates the geometric effect of landmarks to the navigation error in the landmark based 3D vision navigation and introduces the INS/Vision integrated navigation system considering its effect. The integrated system uses the vision navigation results taking into account the dilution of precision for landmark geometry. Also, the integrated system helps the vision navigation to consider it. An indirect filter with feedback structure is designed, in which the position and the attitude errors are measurements of the filter. Performance of the integrated system is evaluated through the computer simulations. Simulation results show that the proposed algorithm works well and that better performance can be expected when the error characteristics of vision navigation are considered.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.37-44
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• 2016

Republic of Korea has established its performance-based navigation (PBN) implementation plan in 2010 for ensuring a smooth transition to PBN operations and relevant new flight procedures are being developed in accordance with the roadmap. Various Navigation aids (NAVAIDs) like global navigation satellite systems (GNSS), distance measuring equipment (DME), VHF omnidirectional range (VOR), inertial navigation system (INS) are used to support PBN procedures. Among them, GNSS would play a central role in PBN implementation. However, vulnerability of satellite navigation signals to artificial and natural interferences has been discovered and various alternative positioning, navigation and timing (APNT) technologies are under development in many countries. In this paper, we study whether continuous PBN operations can be achievable without GNSS signals. As a result, it shows that some of the domestic airports require the construction of APNT in the approach area.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.293-300
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• 2019

In this paper, an Embedded solution for fast navigation and precise positioning of mobile robots by floor features is introduced. Most of navigation systems tend to require high-performance computing unit and high quality sensor data. They can produce high accuracy navigation systems but have limited application due to their high cost. The introduced navigation system is designed to be a low cost solution for a wide range of applications such as toys, mobile service robots and education. The key design idea of the system is a simple localization approach using line features of the floor and delayed localization strategy using topological map. It differs from typical navigation approaches which usually use Simultaneous Localization and Mapping (SLAM) technique with high latency localization. This navigation system is implemented on single board Raspberry Pi B+ computer which has 1.4 GHz processor and Redone mobile robot which has maximum speed of 1.1 m/s.

• Journal of Navigation and Port Research
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• v.34 no.2
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• pp.91-95
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• 2010

Recently IMO and IALA have developed the strategy of e-Navigation and the concepts of VTM to enhance the safety, efficiency and security of vessel traffic and protection of the marine environment. And current technical and functional trends require vessel traffic management systems to be improved so as to control vessel traffic not only in waters of harbour area, but also within EEZ waters. Under the consideration of these circumstances, a three-layered vessel traffic management system was proposed in this paper. The proposed system consists of three sub-systems, called Local VTS, Regional VTS and National VTS, and those sub-systems are designed respectively to be suitable for managing vessel traffic within their own jurisdiction waters.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.8
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• pp.773-779
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• 2006

GPS/INS integration is widely considered as main navigation systems of vehicles since GPS(Global Positioning System) and INS(Inertial Navigation System) have their own strength and weakness, respectively. Accuracy, continuity, integrity, and availability should be provided in navigation systems of vehicles. Ultra-tightly integration can improve these capacities, expecially availability of GPS. Unmanned Expedition Vehicles(UEV) must be robust against Jamming and external impact because UEV have to substitute for a man when they are in the place where they can not be controlled by a man. This paper analyzes the performance of Ultra-tightly integration and compares it with those of loosely integration and tightly integration for some trajectories

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.11a
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• pp.141-144
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• 1997

This paper presents a method of navigation sign recognition in indoor environments using a fuzzy inference for an autonomous mobile robot. In order to adapt to image deformation of a navigation sign resulted from variations of view-points and distances, a multi-labeled template matching(MLTM) method and a dynamic area search method(DASM) are proposed. The DASM is proposed to detect correct feature points among incorrect feature points. Finally sugeno-style fuzzy inference are adopted for recognizing the navigation sign.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.11 no.2
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• pp.7-21
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• 2003

The objective of this study is to evaluate a feasibility of navigation systems appropriate for the Asia-Pacific region. As an independent navigation system, four, five, and six geosynchronous satellite constellations are simulated to provide a navigation system for the region and dilutions of precision of the proposed systems are analyzed and compared.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.80-81
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• 2012

Our society consist of many country's critical infrastructure such as production and distribution of electric power systems, communications technology, tele-communications, financial system, transportation systems when those systems are operated efficiently and normally. Country's critical infrastructure and its application fields of this magnitude rely on more and more P.N.T (Positioning, Navigation. Timing) systems, in which the tele-communications(Timing), financial market(Timing), logistics (Positioning, Navigation, Timing), transportation(Positioning, Navigation. Timing) is shoring. Reliability concerned about the exact position and timing of these critical national infrastructure rely on ability to provide a stable from GPS.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.939-945
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• 2011

We show a new scheme and implementation of maritime data communication systems for GMDSS ship which performs e-Navigation and removes the functional limitation of those systems through comparing to service fee, call processing reliability, and bit rates of all of those systems within communication range at sea. We confirmed available each frequency band communication and application services at sea by experimental result with proposed new system, MF/HF band being useful to a short text message service, VHF band to 9600bps email service, Fleet Broadband Maritime Satellite system to one or more Mbps multimedia service each.