• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.280-286
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• 2022

In order to efficiently collect data, it is essential to locate the facilities and analyze the movement data. The current technology for location collection can collect data using a GPS sensor, but GPS has a strong straightness and low diffraction and reflectance, making it difficult for indoor positioning. In the case of indoor positioning, the location is determined by using wireless network technologies such as Wifi, but there is a problem with low accuracy as the error range reaches 20 to 30 m. In this paper, using BLE 4.2 built in Raspberry Pi, we implement Bluetooth Smart Ready. In detail, a beacon was produced for Advertise, and an experiment was conducted to support the serial port for data transmission/reception. In addition, advertise mode and connection mode were implemented at the same time, and a 3-count gradual algorithm and a quadrangular positioning algorithm were implemented for Bluetooth RSSI error correction. As a result of the experiment, the average error was improved compared to the first correction, and the error rate was also improved compared to before the correction, confirming that the error rate for position measurement was significantly improved.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.385-389
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• 2019

As we become an aging society, the number of dementia patients increases every year (an estimated 10% of the elderly, equating to 1.27 million in 30 years). In addition, 17,000 cases of missing people with disabilities and dementia are reported annually, indicating that more than one person per hour goes missing. More than 50% of those who are lost suffer injuries (some of which are fatal) within 24 hours after going missing. This is why measures are urgently required to ensure safety of the elderly. The core function of the disappearances prevention system proposed by this research group is to identify and respond early to deviations of dementia patients from their homes or facilities by identifying the location of the occurrence of disappearance, so that real-time notifications occur when a they leave the protected area. In addition, multiple receivers and public transportation integrated terminals share information when a patient leaves and uses public transportation to ensure their safe return. Most existing beacon-based positioning service models have fixed signal transmitters and are serviced in the form of transport receivers, but the proposed service model has users wearing the BLE beacon and receivers fixed.

• Journal of Satellite, Information and Communications
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• v.11 no.4
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• pp.63-67
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• 2016

Recently, BLE beacons are widely used in indoor precision positioning systems because of their low battery consumption and low infrastructure cost. However, existing BLE beacon based indoor positioning algorithms are difficult to compensate for position errors due to the user's moving speed. Therefore, we proposed a position error correction algorithm that combines bounced cancellation and minimum distance maintenance algorithm with a positioning error correction method using direction vectors. Experimental results show that the proposed algorithm guarantees superior positioning performance than the existing indoor positioning algorithm and also improves the performance of position error compensation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1162-1179
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• 2017

In this paper, we propose indoor location tracking method using RSSI(Received Signal Strength Indicator) value received from BLE(Bluetooth Low Energy) beacon. Due to the influence of various external environmental factors, it is very difficult to improve the accuracy in indoor location tracking. In order to solve this problem, we propose a novel method of reducing the noise generated in the external environment by using a double Gaussian filter. In addition, the value of the RSSI signal generated in the BLE beacon is different for each device. In this study, we propose a method to allocate additional weights in order to compensate the intensity of signal generated in each device. This makes it possible to improve the accuracy of indoor location tracking using beacons. The experiment results show that the proposed method effectively decrease the RSSI deviation and increase location accuracy. In order to verify the usefulness of this study, we compared the Kalman filter algorithm which is widely used in signal processing. We further performed additional experiments for application area for indoor location service and find that the proposed scheme is useful for BLE-based indoor location service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.643-644
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• 2018

Recently indoor and outdoor location tracking systems are operated in different ways. The indoor positioning method uses WiFi and BLE beacon positioning, and the outdoor positioning uses GPS and PDR. In this paper, it is a device to measure position by using it. It is used to check whether it is indoors or outdoors when measuring based on a smart phone, A automatic conversion method is needed. When using GPS in the room, it is difficult to distinguish the floor or space. We propose a method to solve this problem.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.224-226
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• 2018

자동차 운전자는 운행 할 때 도로 주변을 살펴 여러 상황에 대비한다. 운전자가 주의하여 운전해도 갑자기 도로에 생긴 장애물 때문에 교통사고가 발생 될 수 있다. 만약 운전자가 사전에 도로위에 장애물 발생 정보를 파악할 수 있다면, 교통사고는 어느 정도 감소 할 수 있다고 예상 된다. 본 논문은 운전자가 운행 할 때 사전에 도로위의 장애물의 정보를 운전자에게 알려주는 비콘 서비스를 제안하고자 한다. 본 논문에서는 BLE(Bluetooth Low Energy)을 기반으로 하여 무선 통신 인프라가 없이도 V2V 통신을 구현하여 사전에 도로 사용자가 설치한 장애물을 알려주는 비콘 장치와 장애물 정보를 수집해 운전자에게 알려주는 장치로 구성된다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.9-10
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• 2015

본 논문에서는 블루투스 4.0(BLE) 기반의 비콘을 이용하여, 공항에서 물건을 찾을 때, 물건(가방)에 비콘을 장착하고 비콘의 신호를 받아 알림(Notification)을 주는 System으로써, 사용자의 편리성을 위하여 안드로이드 4.3이상 버전의 스마트 폰 Application으로 개발하였다. 스마트 폰과 비콘 사이에는 블루투스를 기술을 이용하여 통신하며, 비콘은 신호를 송신, 스마트 폰에서는 수신한다. 이러한 기능으로 Estimote사의 공개된 Software Development Kit(이하 SDK)를 바탕으로 개발을 진행하였다. SDK의 대표적인 기능으로 비콘의 정보와 연결 상태를 관리하는 객체, 그리고 Listener를 통해 범위 내 비콘을 탐색하는 기능을 정의할 수 있다. 또한 User Interface를 고려하여 사용자의 편이성과 접근성에 중점을 두어, 화면 구성에 많은 노력을 기울였다. 따라서 사용자의 배경지식, 연령대를 고려하더라도 쉽게 이용이 가능하도록 개발하였다.

• International journal of advanced smart convergence
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• v.6 no.1
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• pp.82-88
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• 2017

Emergency lights and exit signs are an indispensable part of safety precautions for effective evacuation in case of emergency in public buildings. These emergency sign indicates safe escape routes and emergency doors, using an internationally recognizable sign. However visibility of those signs drops drastically in case of emergency situations like fire smoke, etc. and loss of visibility causes serious problems for safety evacuation. This paper propose a novel emergency light and exit sign built-in with Bluetooth Low Energy (BLE) Beacon to assist the emergency self-guiding evacuation using devices for crisis and emergency management to avoid panic condition inside the buildings. In this approach, the emergency light and exit sign with the BLE beacons deployed in the indoor environments and the smart devices detect their indoor positions, direction to move, and next exit sign position from beacon messages and interact with map server in the Internet / Intranet over the available LTE and/or Wi-Fi network connectivity. The map server generate an optimal emergency exit path according to the nearest emergency exit based on a novel graph generation method for less route computation for each smart device. All emergency exit path data interfaces among three system components, the emergency exit signs, map server, and smart devices, have been defined for modular implementation of our emergency evacuation system. The proposed exit sign experimental system has been deployed and evaluated in real-time building environment thoroughly and gives a good evidence that the modular design of the proposed exit sign system and a novel approach to compute emergency exit path route based on the BLE beacon message, map server, and smart devices is competitive and viable.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.12
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• pp.1855-1862
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• 2022

Various indoor location-based services can be provided through indoor presence determination and indoor positioning technology using Beacon. However, since the BLE signal advertised by the beacon has an unstable RSSI due to problems such as multi-path fading, it is difficult to guarantee the accuracy of indoor presence determination. In this paper, data were collected while the classroom door was open to ensure accuracy in various situations. Based on the collected data, we propose an indoor presence determination method considering the characteristics of the signal. The proposed method uses support vector machine, showed about 10% accuracy improvement compared to the results using raw RSSI only. This method has the advantage of being able to accurately determine indoor presence with only one receiver. It is expected that the proposed method can implement a low-cost system for determining indoor presence with high accuracy.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.33-36
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• 2015

기존의 자산관리 시스템으로 대규모 자산을 관리함에 있어 효율적인 RFID나 바코드 등을 이용한 방식들이 있으나 설치과정과 시스템 구성이 복잡하고 비용이 비싸 대중적으로 이용되지 못하고 있다. 본 논문에서는 Bluetooth Low Energy(BLE) 비콘을 이용하여 일상적으로 사용하는 모바일 단말과 웹 등을 이용하여 자산을 관리할 수 있는 경제적인 자산관리 시스템을 제안한다. 나아가, BLE 비콘의 신호 세기에 따른 측정 가능 거리를 분석하여 비콘의 활용에 대한 구체적인 수치를 제시하였고 경제적 측면에서 기존 시스템과 차별화하였음을 보였다.