• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.37-44
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• 2012

This paper describes a compact and novel wireless vital sign sensor at 2.4 GHz that can detect heartbeat and respiration signals. The oscillator circuit incorporates a planar resonator, which functions as a series feedback element as well as a near-field radiator. The periodic movement of a human body during aerobic exercise could cause an input impedance variation of the radiator within near-field range. This variation results in a corresponding change in the oscillation frequency and this change has been utilized for the sensing of human vital signs. In addition, a surface acoustic wave (SAW) filter and power detector have been used to increase the system sensitivity and to transform the frequency variation into a voltage waveform. The experimental results show that the proposed sensor placed 20 mm away from a human body can detect the vital signs very accurately.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.613-618
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• 2019

EMF (Electromagnetic Field) is a valuable resource for living in a knowledge-based information society. The EMF is used in home appliances that make our lives easy and convenient, and in telecommunication devices such as mobile phones, personal computers, medical devices and broadcasting towers. However, the biological hazards associated with EMF exposure are also increasing in signal from telecommunication devices. Studies of the effects of EMF exposure on humans have been conducted for a long time, but it has not yet been demonstrated whether the EMF effect is harmful. In this paper, we examine the electromagnetic field emitted from various electronic devices around living and its effect.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.985-988
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• 2017

Magnetic induction (MI) based communication is one of the near-field communication techniques, which makes use of induced magnetic fields. In order to develop the MI based underwater communication networks, we evaluate and compare the loss performance between direct-MI and MI-waveguide in underwater environment.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.295-296
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• 2018

본 논문은 입 출차를 하는 주차타워의 원리를 바탕으로 NFC를 활용하여 신발을 반 출입하고, IoT 센서를 이용하여 신발의 관리를 편리하게 도와주는 자동 신발타워이다. 수동으로 번호를 입력하던 주차타워와는 다르게 제안한 신발타워는 NFC에 있는 고유ID값을 활용하여 인증된 사용자가 신발장의 센서 터치로 본인의 신발을 반 출입하도록 한다. 신발장 관리 시스템은 신발의 임의적인 반출을 가능하게 하며, IoT센서를 탑재하여 신발장 내부에 향균, 건조, 온도 조절 등의 효과를 탑재하여 신발의 관리를 편리하게 도와주는 기능들을 제공한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.181-188
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• 2017

As smart phone users increase the number of users who insert credit cards into wallet type smart phone cases is increasing. In this paper, we developed an Android application for preventing credit card loss in a wallet type smart phone case using the NFC (Near Field Communication) technology of smart phone. The developed android application uses the NFC reading and writing functions of the smart phone. When the credit card is inserted into the wallet type smart phone case, the android application detects the NFC tag in the credit card and registers credit card information. When the credit card is removed from the smart phone case, the Android application automatically detects the credit card loss and notifies to the user. The user can check and finds the location information of the lost credit card on the map of the Android application. We can easily develop the Android application for preventing credit card loss when a function that automatically detects an leaving NFC tag is added to Android.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.719-723
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• 2016

Owing to the recent increased interest in wireless communication technology and rapid technology development, a range of applied technologies utilizing them are being released. In addition, at school, by adopting an attendance management system using wireless communication technology, attempts to solve problems caused by attendance books are being made. Representative attendance management systems include those using RFID, Bluetooth and clicker. Although these systems have solved the problem of wasting paper and time due to calling and writing attendance, they have other problems of generating additional expenses of purchasing or renting more equipment. To solve all of these problems, this paper suggests prototype system that can manage attendance by using NFC (Near Field Communication), which most smartphones provide. The attendance management system using NFC consists of two applications; one for professors and the other for students. The system solves problems, such as proxy attendance, loss of lesson time and additional cost by automatically managing attendance information using NFC and TCP/IP technologies.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.10
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• pp.25-32
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• 2018

Recently, the complexity of underground utilities has increased and it has became more difficult to identify and manage information about all underground utilities due to changes such as road extension or building relocation. As a result, number of accidents related to underground utilities caused by excavation works or disasters are in rise, and naturally damages as well are increasing due to the accidents. Therefore, there is a need for a management system capable of easily registering or retrieving information of underground utilities from a remote place. In our previous work, we have developed a utility labelling system based on NFC (Near Field Communication) tag and a utility management system based on IoT (Internet of Things). However, in general, there are diverse communication devices and protocols in IoT environment. Therefore, in this paper, we propose management system and IoT gateway that enables smooth communication even in different types of devices based on the previous our work.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.317-324
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• 2016

This paper proposes a message transfer application using smartphone with NFC(Near Field Communication) and GCM(Goolge Cloud Messaging) technology for prevention of personal information leakage. In implementing for the proposed system, we design a NFC-based vehicle status alerts service which make it possible to communicate with smartpone message without phone-number between a car driver and an unspecified person. The application provides message communication mechanism without exposing the real phone number, using the NFC tag written with the driver's smartphone device ID and GCM push messages. Through the evaluation result of the actual implemented application, the proposed system can be efficient technology in protection for leakage of personal information such as personal phone- number in daily life.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.497-502
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• 2012

Power line communication(PLC) is a kind of communication technology, was made use of controling a frequency narrow band, but as the PLC technology developing, in the near future get to the commercial step that is broadband PLC upto 30 MHz. This paper deals with the PLC of electric railway using capacitive signal coupler. An AC arrester for catenary is used as a capacitive signal coupler, has the characteristic of capacitor. As a result of field test, a messenger wire used PLC contain much of conducted noise about overall frequency band and also signal attenuation rate increased with increasing frequency between two points. and the communication speed of PLC used messenger wire is 793kbps at a distance of 40m. Experimental results show the possibility of PLC using a messenger wire and an AC arrester for catenary at electric railway.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.195-196
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• 2016

본 논문은 효율적인 명함 교환을 위하여 NFC를 활용하는 어플리케이션을 개발하였다. 기존의 오프라인 명함은 사용할 때 발생하는 제작비용과 보관상의 어려움이 있다. 이러한 문제점들을 해결하기 위해 개발한 프로젝트는 자신이 사용할 명함을 스마트폰에서 제작하고, 스마트폰에 기본적으로 탑재되어 있는 NFC 기능을 활용하여 명함을 교환하는 App이다. 사용자간 명함교환은 안드로이드 OS에 기본 탑재된 Android Beam 기능을 적용하였고 명함제작을 위해 스마트폰 카메라 또는 기존 사진 이미지를 활용할 수 있어 활용과 교환측면에 장점을 가져 활용성과 편의성이 용이하다.