• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.466-467
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• 2015

ICT 기술의 발달과 활용이 급속하게 증가하고 있는 상황에서 서비스와 시스템의 융합이 활발히 진행되고 있는 가운데 시간과 장소에 구애 받지 않고 스마트 폰을 이용하여 간편하게 이루어질 수 있는 결제시스템 방식에 관심이 늘어나고 있는 것에 대하여 여러 가지 IT기술들이 접목되어 시장에 나타나고 있다. 최근 주목받고 있는 기술로 BLE(Bluetooth Low Energy)기반인 비콘이 있다. BLE 비콘은 에너지 소모율이 적은 것이 가장 큰 특징이며 자동으로 사용자의 위치를 파악하고 서비스를 제공할 수 있다. 비콘이 스마트폰 결제 시스템에 새로운 방식이며 혁신의 바람을 불러온 것은 사실이지만, 비콘 관련 연구 및 개발에서 블루투스 신호를 사용한다는 점을 바탕으로 거리의 정확도의 미흡함과 통신 도달범위가 크다는 것을 관련하여 보안의 위험성을 가지고 있다는 점이 문제로 지적된다. 본 논문에서는 BLE 비콘 결제의 전반적인 시스템을 분석하고 보안의 취약함을 도출하여 그에 따른 요구사항을 연구함으로써 결제시스템의 보안 취약점을 최소화 할 수 있는 대응방안을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.477-479
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• 2015

해킹의 범위가 넓어지고 있는 현 시대에는 컴퓨터 통신 장비만을 해킹 하던 과거와 달리 우리가 살고 있는 21세기에는 컴퓨터 시스템에 한정되지 않고 인간이 사용하는 모든 장비에 통신시스템이 설계되면서 해킹이 가능한 장비들의 범주가 증가하고 있고 인간이 사용하는 모든 통신장비를 해킹하는 사례가 증가하는 추세이다. 특히 스마트 자동차가 나오기 시작하면서 스마트 자동차에 대한 해킹의 위험이 높아지고 있는 상황이다. 블루투스에 대한 보안적인 요소들과 보안 취약점 및 대응방안에 대하여 제안하였다.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.298-306
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• 2016

With the advent of Internet of Things (IoT) technology that allows the communications between things and devices over the Internet, a lot of researches on the IoT services, such as smart home or healthcare, have been progressed. In the existing machine-to-machine (M2M) communications, however, since the underlying link-layer technologies, such as Bluetooth or ZigBee, do not use the Internet Protocol (IP) communication, those technologies are not suitable to provide the IoT services. Accordingly, this paper discusses how to provide the Internet services in the M2M communication, and propose an implementation of the Constrained Application Protocol (CoAP) over 6LoWPAN for providing IoT services in the BLE networks. Based on the implementation, we compared the performance between HTTP and CoAP for IoT communications. From the experimental results, we can see that the CoAP protocol gives better performance than the HTTP protocol with two times higher throughput, 21% faster transmission time, and 22% smaller amount of generated packets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4125-4130
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• 2015

This paper presents the communication performance for the radiation pattern reconfigurable antenna in the wearable device measuring bio signal (temperature, blood pressure, pulse etc.) of human body. The operational frequency is 2.4 - 2.5 GHz, which covers Bluetooth communication bandwidth. The maximum gain of the antennas is 1.96 dBi. The proposed antenna is efficiently transmitting and receiving signal by generating two opposite beam directions using two RF switches (PIN diode). Also, we investigated how radiation pattern changes according to three angles ($30^{\circ}$, $90^{\circ}$, $150^{\circ}$) of Top Loading. In this paper, we measured and compared the SNR (Signal-to-Noise Ratio) and BER (Bit Error Rate) performances of the proposed antennas in the condition between an ideal environment of anechoic chamber and smart house existing practical electromagnetic interferences (Universal Software Radio Peripheral, USRP). Throughout the comparing the results of the measurement of two cases, we found that the SNR is degraded over 5dB in average and BER is increased over ten times in maximum, therefore, it is confirmed that the error rate of receiving signal is increased. The measured results of SNR and BER value in this paper able to expect the performance degrading by the interference from the electromagnetic devices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4193-4199
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• 2012

In this study, the intelligent robot equipped with an Android-based smartphone to enable the implementation of the performance of smartphone applications and robot platform has been designed and implemented. Smart phone that have touch screen, sound input/output, network and various sensor functions to robot platform that have simplicity function of power and motor etc. graft together and embodied so that can achieve function of remote control, home automation, game machine, R-running race etc. Phone used in the study of the Bluetooth communication sending and receiving data between the robot and from a remote computer over the Internet via WI-FI is designed to perform communication.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.39-42
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• 2002

RS-232C는 정보기기들을 연결하는 직렬통신 표준으로, 간단한 구조로 인해, 복잡한 요구 조건이 없는 상용 기기들의 제어 및 감시용으로 사용되고 있다. 최근 무선동신기술이 발전함에 따라, 저가격의 무선통신 기술을 활용하여 무선 RS-232C에 대한 요구가 늘어나고 있다. 무선 RS-232C로 기존 유선의 RS-232C를 대체함으로서, 기존 시스템의 변경없이 편리한 접속기능을 대체한 수 있을 것이다. 본 논문에서는 유선 RS-232C를 대체하는 무선 RS-232C 모듈을 채용하여, 전력제어에 사용하는 배전자동화 장치의 관리를 간편하게 하는 시스템의 구현에 대해서 다루고 있다. 배전 자동화시스템은 일종의 SCADA시스템의 일부로서, 통신 프로토콜로서 산업용 DNP3.0을 사용하고 있다. 무선 RS-232C 링크의 신뢰성을 확보하기 위하여, 무선 구간에 DNP3.0을 채택하였으며, 무선 통신방식으로는 무선 RF, 블루투스(Bluetooth), 무선랜(wireless LAN)등 3가지 방식을 채용하여, 설계, 구현내용을 기술하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.173-179
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• 2017

Autobike is insufficient of car navigation informations and high of accident dangerousness comparing to car. So if a system providing autobike driver's driving information and e-call function is developed using smart helmet consisting of collision perception sensor, rear camera, bluetooth communication module, MCU and HUD, It is very useful and can decrease of person's damage and handle expeditious traffic accident during autobike accident. In this paper, when this, "Providing system of autobike driver's information and e-call function", software is developed, a proper analysis and design method for practical affairs try to be presented due to showing software development analysis method, architecture of hardware block-diagram, flowchart and UI design.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1349-1355
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• 2008

Recently many short-range transceiver systems, such as ZigBee, Bluetooth and RFID(Radio Frequency Identification), have been developed. These systems are mostly low-power transceivers. In the near future many more low-power transceivers are appeared for WPAN(Wireless Personal Area Network) and interference mitigation technologies are necessary to the low-power transceivers for using frequency resources efficiently. In this paper we consider two methods for sharing frequency resources. The first case is that a frequency band previously assigned fer a certain system is shared and the second case is that the white frequency band is shared. We study the method and conditions for sharing frequency resources in the above two cases. When a frequency band is shared with ZigBee, RFID, DCP (Digital Cordless Phone) and Bluetooth as an example for the first case, the sharing conditions are investigated and the results are presented. We propose a balancing factor to maintain an equal transmitting conditions between systems having a different interference mitigation technique. In the interference simulation we use FH(Frequency Hopping) as a reference system and 0.9 of a balancing factor for LBT(Listen Before Talk) and 0.8 for DS(Direct Spreading). From the simulation results we know that a balancing factor reduces interference probability therefore many more systems can be operated in the same frequency bands compared with the case without using a balancing factor.

• Convergence Security Journal
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• v.8 no.3
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• pp.73-81
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• 2008

We can find easily about researches or technical development that deal with grasping the location of an object with GPS(Global Positioning System) in order to use them as a useful information. Most researches or technical development on application of tracing have been developed for the purpose of tracing objects in broad area as physical distribution or transportation, but recently, there are many researches on tracing materials in premise area as a fork lift, carts, or the equipment of work. In general, a system that utilizes location information of objects needs data communication network to transmit location data and it ensures data communication network by using common networks(SK, LG, KFT) or wireless LAN. However these two methods need monthly payment for the rental fee or require considerable amount of investment for the early stage so it is difficult to use them merely for tracing premise subjects. This study was conducted to build a tracing system for premise area by local area RF relay algorithm with low cost applying RF relay algorithm to local area wireless communication(ZIGBEE, 424MHz, Bluetooth, 900MHz) system in order to supplement these demerits and included relay algorithm, RF locating information terminal, local area RF gab-fillers, a plan for collection server of locating information, and the way of realization as they are needed in this system. I consider that this study would be applicable with flexibility in the industry area that needs tracing solution within a specific area or needs ensuring data communication network, to transmit data in ubiquitous environment, by easier and more rapid way with lower cost.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.79-88
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• 2006

In this paper, we designed and implemented ubiquitous u-Health system using RFE and ZigBee. We made a wireless protocol Kit which combines RFE Tag recognition and ZigBee data communication capability. The software is designed and developed on the TinyOS. Wireless communication technologies which hold multi-protocol stacks with RFID and result in the wireless ubiquitous world could be Bluetooth, ZigBee, 802.11x WLAN and so on. The environments that the suggested u-Health system may be used is un-manned nursing, which would be utilized in dense sensor networks such as a hospital. The the size of devices with RFID and ZigBee will be so smaller and smaller as a bracelet, a wrist watch and a ring. The combined wireless RFID-ZigBee system could be applied to applications which requires some actions corresponding to the collected (or sensed) information in WBAN(Wireless Body Area Network) and/or WPAN(Wireless Person Area Network). The proposed ubiquitous u-Health system displays some text-type alert message on LCD which is attached to the system or gives voice alert message to the adequate node users. RFE will be used as various combinations with other wireless technologies for some application-specific purposes.