• Journal of Digital Policy
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• v.2 no.4
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• pp.11-15
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• 2023

Recently, a fire suddenly broke out in a crowded theater, and many people were unable to find an escape route, becoming entangled, injured, and suffocating from smoke inhalation, resulting in a large-scale fire accident. Even though most of the people were young, they were unable to evacuate. If they had been elderly, it could have resulted in greater casualties. In particular, since it is difficult to receive accurate location information from GPS indoor, there is an urgent need for location-based services using beacons and an emergency evacuation system that intuitively shows evacuation routes in augmented reality using smart-phones. In this paper, an augmented reality-based emergency evacuation smartphone app was developed based on identifying fire locations and evacuation routes using beacons and fire sensors (IoT). In the future, if the proposed system is applied to indoor spaces where people are crowded, rapid evacuation will be possible even in a sudden fire accident, minimizing human damage.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.157-162
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• 2014

The international COSPAS-SARSAT program is a satellite-based search and rescue distress alert detection and information distribution system and best known as the system that detects and locates emergency beacons activated by aircraft, ships and so on. However, the current message format of the system is not encrypted so that, if the rescue signal can be intercepted by the unintended receivers, the subsequent rescue activities can be handled in a hostile environment. So, this article concerns how to deal with the rescue signals in a secure way and proposes some adequate encryption methods and the corresponding key management.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.9
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• pp.723-732
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• 2016

This paper proposes an approach to fused navigation of an unmanned surface vehicle(USV) and to detection of the outlier or interference of global positioning system(GPS). The method fuses available sensor measurements through extended Kalman filter(EKF) to find the location and attitude of the USV. The method uses error covariance of EKF for detection of GPS outlier or interference. When outlier or interference of the GPS is detected, the method excludes GPS data from navigation process. The measurements to be fused for the navigation are GPS, acceleration, angular rate, magnetic field, linear velocity, range and bearing to acoustic beacons. The method is tested through simulated data and measurement data produced through ground navigation. The results show that the method detects GPS outlier or interference as well as the GPS recovery, which frees navigation from the problem of GPS abnormality.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.67-73
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• 2018

In this paper, we propose an electronic attendance management system using the bluetooth function of the beacon and BLE advertising function of the smart phone. In the beacon-only bluetooth attendance confirmation system, it is needed more than one beacons according to the class room sizes. A BLE advertising function based attendance confirmation system can not provide the information about the location of the attendances. In the proposed system, we can identify the location of the instructor using the beacon of the class room, and confirm the attendances by checking the position of the attendances's smart phone. In this system, we can achieves the goals of electronic attendance management system using only one beacon per a class room.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.1 s.12
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• pp.47-57
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• 2007

In this paper, optimal parameters of a hopping pilot beacon are analyzed in a CDMA mobile cellular network. The hopping pilot beacon is used for inter-frequency handoff. It can reduce the number of pilot beacons needed for the inter-frequency handoff by transmitting neighbor frequency pilots periodically through a pilot beacon. The optimal parameters for transmission time and period of the hopping pilot bacon are derived by mathematical approach. It is highly recommended that the optimal values for the hopping pilot beacon under various operation environments.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.1
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• pp.70-74
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• 2006

Cospas-Sarsat, an international satellite system for search and rescue, started operating in early 1980's and has been credited with saving thousands of lives since then. Hundreds of thousands of aviators, mariners and land users worldwide are equipped with Cospas-Sarsat distress beacons, which could help save their lives in emergency situations anywhere in the world. This paper outlines the evolution of the system and describes how satellites are constantly circling the globe monitoring for rescue signals, while tracking stations on six continents receive the satellite signals, compute the locations of the distress events and forward the calls for help to the appropriate rescue authorities. Therefore, this paper points out the importance of developing of technologies of Hybrid Aviation Wireless SAR Equipment and also proposes to make it localized.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1040-1044
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• 2005

This paper presents a method for the robot localization and calibration using the ultrasonic and the radio frequency. The distance between the receiver and a beacon can be computed by using the difference between times of flight. The presented method uses the gradient of the maximum amplitude of the ultrasonic in order to measure the time of flight precisely. The measured three distances between the receiver and the beacon are used to compute the robot position by the direct inverse method and the iterated least square approximation method. This paper is defined the calibration as the problem to find the location of 3 beacons and 3 robots, and presents 3 methods for it and found the 2B2R method as the best among them.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.4
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• pp.330-336
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• 1996

An real-time active beacon localization system for mobile robots is developed and implemented. This system permits the estimation of robot positions when detecting light sources by PSD(Position Sensitive Detector) sensor which are placed sparsely over the robots work space as beacons(or landmarks). An LSE(Least Square Estimation) method is introduced to calibrate the internal parameters of a model for the beacon and robot position. The proposed system has two operational modes of position estimation. One is the initial position calculation by the detection of two or more light sources positions of which are known. The other is the continuous position compensation that calculates the position and heading of the robot using the IEKF(Iterated Extended Kalman Filter) applied to the beacon and dead-reckoning data. Practical experiments show that the estimated position obtained by this system is precise enough to be useful for the navigation of robots.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1155-1160
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• 2007

This paper presents position error for the robot localization system using the ultrasonic wave. The distance between the receiver and a beacon can be computed by using the difference between times of flight. The distance information measured by ultrasonic wave has errors. The position is calculated by distances, and this error is caused by distance errors. The position error is different from receiver¡s position. And the position is also calculated by beacon location. This paper calculates worst case position error within measuring area, and finds beacons location to reduce the position error.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.4
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• pp.100-110
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• 2005

The worldwide satellite system for search and rescue has been in operation since 1982 and has assisted in the rescue of thousands of lives in distress. Aviators, mariners and land users being equipped with distress beacons are capable of transmitting distress signals to the satellites in emergency situations anywhere in the world. This paper describes the configuration of the search and rescue satellite system, principles of its operation, and how the system is utilized to process the distress events. Also, this paper points out the importance of development of technologies of user equipment and proposes an experimental program for technology development using domestic satellites.