• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.3-11
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• 2017

Research and development are being conducted to apply low-power Bluetooth (BLE) technology to IoT (Internet of Things) applications. The characteristic of this application environment is that many piconets can operate in the same space. Therefore, interference between homogeneous networks is likely to occur. In the BLE data channel, adaptive frequency hopping (AFH) scheme is used among the 37 frequency channels, and the master and the slave communicate while changing the carrier frequency. If there are multiple BLE piconets in the same space, there is a risk of frequency collision and packet errors will occur. In this paper, we analyze the packet collision probability due to cochannel interference in multiple asynchronous BLE piconet environments. Specifically, we analyzed packet collision probability according to the number of concurrently operating BLE piconets with the ratio of connection interval to connection event length as the main parameters. The analysis result can be used to set connection event related parameters for a desired packet collision probability according to the number of users having BLE devices in a given space.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.309-315
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• 2017

Recently it has drawn much attention on the technologies about Internet of Things (IoT) which connects objects with constrained resource and heterogenous communication module in order to communicate information via internet. We propose a real-time sensor monitoring system based on IPv6 over Bluetooth Low Energy (BLE), which is included in Bluetooth 4.2 Specification. Since this system uses a publish-subsribe based IoT protocol, so called Message Queueing Telemetry Transport (MQTT), neither transforming network data nor any proxy server is needed in order to transmit data. Through the web client connected to this system, you can monitor sensor data sent by BLE device in real-time, intermediated via MQTT broker and then delivered to the client via HTTP and websocket protocol. In this paper we evaluated network capacity and availability of the implemented test platform. Thus by using this system it is possible to make development cost low and to construct IoT network with heterogenous devices easily.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.89-94
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• 2018

This paper investigated the design method of the smart sensor for implementing IoT (Internet of Things) service. The power supply of sensor consistently acquisting data is based on the energy harvesting technology and designed with piezoelectric transducer not affected by surrounding circumstances. The wireless communication interface for the transmission of data is designed with BLE (Bluetooth Low Energy). BLE is highly adequate wireless communication technology for low power consumption and short distance wireless communication. The main application of BLE is beacon whose usage range is extended from O2O (Online to Offline) service, navigator based on indoor positioning technology, and anti-theft/lost child prevention service to mobile game. This paper studied the method to extend wireless coverage for complementing the short wireless transmission distance of BLE. The wireless sensor network based on CATV network is proposed for the easy construction of BLE sensor network and extended wireless coverage.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.900-902
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• 2016

사물인터넷은 최근 몇 년간 급격한 발전을 이루었으며 발전을 바탕으로 삶의 질 향상과 상업적인 가치가 큰 스마트 환경을 구축하였다. 스마트 환경 구축을 위해서는 각각 사물들이 사용하는 통신 프로토콜 간 통신이 되어야 한다. 그러나 통신 프로토콜 간 서로 다른 통신 규약을 가지기 때문에 통신이 안 되는 이질성 문제가 있으며 이러한 문제를 해결하기 위해서는 DDS(Data Distribution Service) 기반의 어댑터(Adaptor)가 필요하다. 본 논문은 최근 각광받고 있는 BLE(Bluetooth Low Energy)를 사물 인터넷에 적용하기 위해 DDS 기반의 BLE 어댑터를 제안한다. 이러한 BLE 어댑터를 통하여 BLE와 RFID(Radio-Frequency Identification), LTE(Long-Term Evolution), 그리고 지그비(ZigBee) 등 다른 통신 프로토콜 간 이질성 문제를 해결함으로써 서로 다른 데이터를 활용할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1735-1754
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• 2022

The reliability and performance of WiFi need optimization because of the rising number of WiFi users day by day. A highlighted point is saving power while transmitting and receiving packets using WiFi devices. Wake-on-Wlan (WoW) is also implemented to improve energy consumption, but it also needs betterment. This paper will introduce universal ideas to transmit and receive packets using low-power technology like Bluetooth or BLE (Bluetooth low energy). While looking for power-saving ways in this research, WiFi connection and maintenance also take care using lesser power-consuming technology. Identifying different use-cases where low power technology can help save energy and maintain 802.11 connection is part of the research. In addition, the proposed method discuss energy saving with unicast and broadcast/multicast data. Calculation of power-saving and comparison with standalone WiFi usage clearly shows the effectiveness of the proposed method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.529-530
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• 2016

When the mountain accident occurred, the accident victims should inform anyone of information of the location and accident situation rapidly. But if you are in the radio shadow area where you cannot use GPS, 3G/4G, and wireless communication, you can't inform someone your accidents. In this paper, we suggest the emergency rescue request notification service in situation that victims can't report their accidents. This service is to send request message for rescue in radio shadow area, in mountain accident, by BLE(Bluetooth Low Energy).

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.36-37
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• 2021

OSC(Off-Site Construction) is regarded as a faster and more economical method in the construction industry, and the attention towards the OSC is growing. In the modular construction process, which is one type of OSC, accurate identification of a module is essential. Because the installation position and the MEP(Mechanical, Electrical, and Plumbing) composition are distinct between modules, a defect in the finishing or junction area is likely to happen during the construction process. This study suggested the modular construction process by applying a beacon receiver using BLE(Bluetooth Low Energy) technology on each module. Construction quality management would be improved using the location and assembly data, particularly for a different module in modular construction.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.55 no.6
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• pp.604-613
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• 2018

In this study, we analyzed the variations in the received signal strength index (RSSI) measured from Bluetooth beacons based on the strength and propagation direction of Bluetooth low energy (BLE) signal. Using a smartphone, we performed field experiments to investigate RSSI variations in the BLE signal transmitted by non-directional and directional beacons in an amethyst mine. In case of non-directional beacons, as the distance between the Bluetooth beacon and smartphone decreased, the RSSI increases, whereas as the BLE signal strength increased, the RSSI average gradually increased. The mean value of RSSI measured from the directional beacons was changed without relation to the facing angle between the Bluetooth beacon and smartphone. The results of this study can be used as basic data for developing a Bluetooth beacon-based proximity warning system for underground mines.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.33-46
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• 2017

Increasing popularity of smartphone is creating many changes in payment market sector also. The new fin-tech and simple mobile payment service have provided convenience as well as various benefits and value-added services to create new payment culture. However, the infrastructure of offline shops is too poor for users to use the simple mobile payment services in Korea. There are several reasons why the support of simple mobile payment services by offline shops has reached the limit in Korea. They include the reluctance of shop owners due to highly priced devices, the failure of NFC of the leading offline payment infrastructure to support iOS, the services that are biased to the specific manufacturers and smartphones (Samsung Pay and LG Pay), prefer large shops (SSG Pay and L PAY), and focus on online transactions. This study used the Bluetooth technology that is the standard feature built in all smartphone to expand the offline shops that accept the simple mobile payment services ensuring universality and scalability from the convenience of customer's and service provider's aspects. Applying the same payment scene as the existing NFC payment method from the user's aspect and the Bluetooth technology from the service provider's aspect enables support of all smartphones and offering value-added services such as electronic receipt and promotions through the large-capacity bidirectional data transfer. This study is intended to review the simple mobile payment services in Korea and other countries, propose the simple mobile payment service model for Korea by analyzing the Bluetooth technology and preceding studies of payment services using BLE technology, and develop the pilot system using the BLE technology to verify the proposed system with actual shops.