• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.225-231
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• 2024

In this article, a new approach is presented to improve the unchangeable function of a ready-made millimeter-wave antenna system. By designing a metamaterial surface appropriate for the given geometry and fixed electrical characteristics of the device, the properties of the radiated fields of the RF product are changed to have directivity and higher antenna gain. Unlike other designs using periodic metamaterials for a single patch, an aperiodic metasurface is developed to handle two patches. For a higher received signal strength and a longer RF path in the 24 GHz-radio link, an aperiodic metasurface enhances the radiated fields by 10 dB.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.436-442
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• 2015

In this paper, we develop an indoor localization device which embeds localization information into indoor light-emitting-diodes (LED) lighting systems. The key idea of our device is the use of the newly proposed "bit stuffing method". Through the use of stuff bits, our device is able to measure signal strengths even in transient states, which prohibits interference between lighting signals. The stuff bits also scatter the parts of the signal where the LED is turned on, thus provides quality indoor lighting. Additionally, for the indoor localization system based on RSSI and TDM to be practical, we propose methods for the control of LED lamps and compensation of received signals. The effectiveness of the proposed scheme is validated through experiments with a low-cost implementation including an indoor navigation task.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.606-608
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• 2015

In order to bear a relationship between the devices in the IoT environment whereby the task of navigating the device and relationship should be preceded before. The new device transmits a search signal in order to find a device and a peripheral device that receives this will determine the distance information of the device and determines the intensity of the transmitted signal. M2M (Machine to Machine) method has been used in conventional sends the search signal to all of the peripheral devices in a single device, a peripheral device that is greater the search time becomes long, a problem that a loss of information, the more devices that are far there is. In this paper, a method to compensate for problems of existing methods of M2M devices and new shortening of the search time when the search for the peripheral device, an algorithm to reduce the information loss of time to send and receive signals from the navigation device and away proposals were discussed and used in the field.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.1
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• pp.87-94
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• 2016

Although studies and investments on electro-magnetic fields in terrestrial areas are being conducted, they are not applied to a ship. Especially ship is consist of Top Side, Bridge, and Engine Room. Top Side is mounted Antenna and radar. Bridge is mounted navigation and navigation equipment that have a safe voyage. Finally, Engine Room is mounted switchboard and this is used to ship propulsion system. Therefore the purpose of this paper is for suggesting optimized standard to apply to marine environment through analyzing electromagnetic wave environment in ship. For this, we were measured EMF in Hanbada ship in Korea Maritime and Ocean University and we compared and analyzed to measured values in Korea standards and international standards. Consequently, Engine Room of ship for the identified that there are limits to apply. The proposed results of this research will be expected to utilize for establishing standard a plan for EMF in ship.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.936-942
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• 2022

While indoor vehicle navigation is an essential component in large-scale parking garages of major cities, technical limitations and challenging propagation environments considerably degrade the accuracy of existing localization techniques. This paper proposes a proximity detection scheme using low-cost beacons where a handheld mobile device within a moving vehicle autonomously detects its approximate position and moving direction by only observing Received Signal Strength (RSS) values of beacon signals. The proposed approach essentially exploits the differential RSS technique of multi-directional beams to reduce the impact of the environment, vehicle, and mobile device. A low-cost multi-directional beacon prototype is developed using Bluetooth technology. The localization performance is evaluated using 96 beacons in an underground parking garage within an area of 394.8m×304.3m. Experimental results show that the 90th percentile of the average proximity detection error is 0.8m. Furthermore, our proposed scheme provides robust proximity detection performance with various vehicles and mobile devices.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.269-274
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• 2015

As smart device companies such as Google or Apple develop competitive mobile-based automotive operating systems and navigation systems, the range of choice for users in such markets is expanding. Navigation systems equipped with mobile operating systems have increased convenience for users. However, since an API for the POI databases used in navigation systems doesn't exist, the number of applications using POI data is insufficient. In this paper, we designed and implemented system calls for navigation operating systems with a focus on POI search, in order to resolve such limitations. The system calls support set-based POI search functions, and therefore provides solutions to search performance degradation problems caused by false inputs. As a result of performance evaluation, not only did the search performance improve, but there was also no problem in applying APIs in applications.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.29-34
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• 2008

Demand for car navigation systems has been an explosive increase because of prevalence of owner-drivers, spare time spread, and so on. In addition, car navigation systems are achieving a rapid growth to be the important part of telematics industry with services such as real-time traffic information and DMB(Digital Multimedia Broadcasting). The network data, one of the composition components in car navigation systems, is most important component because that is abstract of real world road network and base data in pathfinding. However most of the car navigation systems have been stand-alone system. Thus user's network data becomes outdated according to the time passing and does not reflect the change of road information in real world. To overcome this problem, users have to update network data in car navigation systems periodically. This method is quite cumbersome process. For this reason, this study proposed a new update method to serve the difference network data on user's device and the real world in real time, and simulated to verify.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.123-124
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• 2012

Over the past decades, information and communication service providing safe and efficient navigation have been tried in maritime area. However, there were provided different ways such as different protocol or different policy. It made hard to serve efficiently. The introduction of MSI as a part of e-navigation development can be a kind of concepts to solve this problem. This paper tries to suggest a conceptual design of onboard application middleware to be able to communicate the shore-side maritime safety information system, take into account the reuse of open-source software.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.139-141
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• 2021

In the maritime digital forensic part, it is very important and difficult process that analysis of data and information with vessel navigation system's binary log data for situation awareness of maritime accident. In recent years, anaysis of vessel's navigation system's trajectory information is an essential element of maritime accident investigation for vessel digital forensic process. So, we analysis of maritime navigation systems of vessel and feature of device and environments. In the future, we will research on information of ship's trajectory and movement for useful forensic service.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.833-838
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• 2011

X-ray device used in the diagnosis has made possible to have more effective and accurate diagnosis, powered by the development of various devices. Based on this, X-ray device has become the most basic and essential diagnostic equipment in clinical medicine. At present, in the image acquisition field using X-ray, the use of Digital radiography which is useful in the acquisition time reduction and transfer of images and is possible to have the dose reduction has expanded. With the structure using one detector, this DR device has disadvantages in that it needs structural changes unlike existing X-ray and the detector should be moved to the desired position depending on the shooting location. Therefore, in this study, using BLDC(Brushless direct current) motor and PID(Proportional integral differential) control method, the automatic control system of 3-axis which is upward and downward, left and right and rotation of detector where having the most movement in DR was designed and produced and its performance was evaluated.