• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.99-106
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• 2017

Audible Pedestrian Signal(APS) is an additional equipment to provide information about pedestrian signals in non-visual formats such as audible tones and verbal messages. It can provide information to pedestrians about the location and directions of a crosswalk, and the traffic signal status. In general, a pedestrian who is visually impaired uses a 358.5MHz wireless remote controller to activate the APS and crosses at the crosswalk with the help of the APS. The existing APS can only receive an activation message from the remote controller. Therefore, the APS has an issue, especially at intersections, that all APSs within the communication range of the remote controller are activated simultaneously. It makes to confuse the visual impaired pedestrians. In this paper, we propose a BLE-enabled APS that can enable two-way communication via Bluetooth with a smartphone. The proposed system solves the problem and provides them with additional information, so that visually impaired pedestrians can cross at the crosswalk more conveniently.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.11
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• pp.403-410
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• 2016

IoT(Internet of Things) has purpose for providing new kind of service though interaction with everything. With development of IoT, computer model which is based on internet is changed to distributed connection model between heterogeneous things. There is a problem that it is impossible to connect between each other different protocols. To solve this problem, we should abstract each of things of data through using adaptor of middleware structure in order to make consistent data unit. In this paper, we propose BLE(Bluetooth Low Energy) adaptor, which is interaction with things, based on DDS(Data Distribution Service) that is real-time standard middleware. It is possible to data interaction between BLE Devices as well as two-way data interaction with different protocol devices. Also existing BLE Devices and study have a problem that Data exchange without using a standard data format of a profile defined by the Bluetooth SIG. Using the data formats defined independently by a problem that should not exchange data according to the type and manufacturer of the device BLE. The BLE adapter to solve this problem, the classification and analysis of the 12 stand profile was applied to create a profile based on the standard data format. It is possible to get wide interoperability of not affected on the BLE devices type and manufacturer of the device because it is applied a profile that standard data format.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.837-838
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• 2016

최근 IoT 기술의 발전과 함께 스마트홈 기술의 발달과 Drone을 사용하는 사용자가 꾸준히 늘어나고 있는 추세이다. 스마트홈 시스템의 보안카메라는 정해진 구역을 모니터링 할 수 밖에 없다는 단점을 가지고 있다. 이러한 한계를 극복하고자, 본 논문에서는 사용자가 입력한 목적지로 실내에 미리 배치된 Drone이 이동하여 해당 목적지를 비춰줄 수 있도록 실내 보안카메라 기술을 Drone으로 대체할 수 있는 방법을 제안한다. 목적지를 인식하기 위해 실내에 위치한 Drone과 목적지의 위치값을 알아야 한다. 실내에선 GPS 좌표값을 알 수 없기 때문에 BLE Beacon이 발생시키는 신호를 이용하여 상호간의 통신을 통해 위치, 거리를 계산하도록 한다. 이러한 방식을 적용시킨다면 매번 모니터링이 필요한 구역에 새로 보안카메라를 설치하거나 배선공사하는 불편함 없이 하나의 Drone 하드웨어를 이용한 전방위 모니터링이 가능해 질 것으로 기대한다.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.223-234
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• 2017

The audible pedestrian signal (APS) is an add-on device which connects to the pedestrian signaling device and informs the contents and changes of the signaling by sound. It provides walking direction information of the pedestrian crossing so that the blind people can safely cross the pedestrian crossing. In an intersection where a plurality of audible pedestrian signal (APS) are installed at an intersection crosswalk, existing audible pedestrian signal (APS) operate simultaneously in the communication radius of a wireless remote controller, which may cause confusion for the blind people and the public may complain about the noise. In this paper, we developed a BLE (Bluetooth Low Energy)-based audible pedestrian signal (APS) system capable of supporting two-way communications with a smart-phone that can cross the intersection safely and improve the walking comfort and traffic safety for the blind people. The proposed method is a method in which the BLE beacon communication based audible pedestrian signal (APS) presents active service to the blind people, and the existing audible pedestrian signal (APS) is a way of requesting the passive service by the blind people with the wireless remote control by the unidirectional communication based on 358Mhz. The developed system is installed in the crossroad of Doma-dong, Seo-gu, Daejeon, and it is tested and operated by the blind people. The satisfaction evaluation and analysis of the audible pedestrian signal (APS) for the blind people have good results and are planned to be expanded in the future.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.1
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• pp.8-13
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• 2022

This paper investigates the method to implement a RF (Radio Frequency) energy harvesting sensor node and to build a sensor network using a CATV network and a leaky coaxial cable. The power supply of a sensor node is designed with the WPTS (Wireless Power Transfer System) receiver operating at 915MHz. A sensor network has limited coverage by the loss of RF signal at a wireless transmission link. The paper proposes to build a sensor network that the BLE signal of a sensor and the signal of a WPTS power transmitter are transmitted through a coaxial cable of a CATV network by utilizing WOC (WiFi over Coax) technology and radiates at a leaky coaxial cable. The length of a leaky coaxial cable and the total loss of a wire link are allowed to the point that the RSSI of a sensor node is more than the minimum value (-78dBm) and lead to extend wireless coverage.

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.249-251
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• 2014

휴대폰 및 전자기기의 보급과 소비가 증가하면서 기기를 사용함의 기본이 되는 전력 공급의 문제가 대두되고 있는 상황이다. 이에 따라 소비자들의 가장 큰 관심은 기기의 전력을 얼마나 효율적으로 사용할 수 있느냐, 잦은 베터리의 충전을 최소화 할 수 있느냐에 쏠려있다. 사용량이 증가하는 추세에 의해 언제 어디서든 거리의 제한을 받지 않고 기기의 충전을 할 수 있는 무선 충전 기술 개발이 각광을 받고 있는 현실이다. 본 논문에서는 무선 충전의 효율성과 경쟁력을 확보할 수 있는 대안 기술로 현재 BLE기술 기반의 프로토콜을 사용하여 전력손실을 최소화 하는 근거리 통신 기술 서비스와 무선 충전 기술을 융합하는 시스템에 대해 연구하고자 한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1085-1092
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• 2018

Recently, Internet (IoT) and big data have been utilized in various fields such as medical, military and sports. Korea Nazarene University is a rehabilitation-welfare university with about 300 students with disabilities. This paper proposes a smart campus that provides the optimal path for the calculation of the route and risk avoidance using the BLE beacon and the 3-axis acceleration sensor when the students with disabilities move in the campus both indoors and outdoors. So we can manage the big data and sensor-based IoT technology for students with disabilities.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.72-76
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• 2023

The mobile card system used for mobile access control is connected to the door lock mounted on the door, enabling non-contact control. The RSSI (Received Signal Strength Indicator) of the BLE (Bluetooth Low Energy) communication packet used here can help to know the direction and distance of the mobile device. In this study, the desirable access control distance was calculated and implemented by setting the RSSI of the transmitter of the BLE packet used in mobile access control and processing the RSSI of the receiver.

• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.37-42
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• 2018

Recently, there have been many studies on the IoT environment in which the sensors attached to the equipment automatically transmit and process the site information in real time through the network to control the equipment. The core of such a system is a network for data transmission and reception, and a wired network with wide transmission distance is a priority. However, in the case of a wired network, there is a problem that the time and cost consumed to configure the communication is higher than that of the wireless. In this paper, we propose LPWA - based wireless data transmission system using LPWA and BLE communication to solve this problem. The proposed system collects data from equipment through BLE and transmits data to the server using LPWA. Experimental results show that the spreading factor of maximum length of LPWA is 8, and the minimum length is 9.