• Journal of Internet Computing and Services
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• v.15 no.2
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• pp.9-18
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• 2014

The sensors attached on/in a person are moved since human body frequency changes their activity, therefore in wireless body area networks, nodal mobility and non-line-of-sight condition will impact on performance of networks such as energy efficiency and reliable communication. We then proposed schemes which study on forwarding decisions against frequent change of topology and channel conditions to increase reliable connections and improve energy efficiency. In this work, we control the size of packets, forwarding rate based on ratio of input links and output links at each node. We also robust the network topology by extending the peer to peer IEEE 802.15.4-based. The adaptive topology from chain-based to grid-based can optimal our schemes. The simulation shows that these approaches are not only extending network lifetime to 48.2 percent but also increase around 6.08 percent the packet delivery ratio. The "hot spots" problem is also resolved with this approach.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.384-385
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• 2008

본 논문은 전력선이나 무선기지국 처에서 방축된 전자파를 인터넷, 휴대폰 등 통신수단을 이용하여 원격지에서 실시간으로 측정, 감시할 수 있도록 고안된 전자파 인체노출 원격측정 시스템에 대하여 기술한다. 본 시스템은 측정 자동화 및 무인차 개념이 도입되었으며, 국제규격에서 권고한 측정프로토콜에 따라 측정수행이 되므로 전자파인체노출기준의 적합성 여부론 판단하는 표준측정 시스템으로도 활용될 수 있다.

• Electronics and Telecommunications Trends
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• v.31 no.6
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• pp.31-38
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• 2016

인체에 근접한 다양한 휴대 정보 단말기 간의 통신망을 무선으로 구축하는 Wireless Body Area Network(WBAN) 분야에 관한 연구 결과가 국내외에서 지속적으로 발표되고 있다. 이 가운데 인체통신 기술은 인체를 신호의 전송경로로 활용하여 단말기들 간의 연결을 위한 케이블이 필요하지 않으며, 저전력 고속 데이터 전송이 가능하여 WBAN에 가장 적합한 통신 기술로 손꼽힌다. 더불어 인체통신 기술은 사용자의 간단한 접촉을 기반으로 인체 네트워크를 구성하므로 웨어러블 디바이스/센서/단말 및 임플란트 디바이스 분야에 반드시 필요한 핵심 통신 기술로 주목받고 있다. 본고에서는 WBAN에서 최근 인체통신 기술의 개발 동향과 활용 분야 및 표준화 동향에 관하여 살펴보고자 한다.

• Journal of the Korea Computer Graphics Society
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• v.3 no.2
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• pp.45-53
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• 1997

본 논문에서는 초고속 통신망을 이용한 고급 삼차원 정보 제공을 위하여 개발한 두 가지 WWW (World Wide Web) 정보 시스템에 대하여 설명하고자 한다. 하나는 인체 골격 교육 시스템으로, 서버와 브라우저로 구성하여 인체의 골격 구성을 WWW에서 삼차원화시켜 보여주고 사용자가 원하는 부위를 직접 접근하고 관찰할 수 있게 하는 시스템 개발 방법을 기술한다. 인체 골격의 방대한 데이터를 사용자에게 효과적으로 제공하기 위한 서버 구축의 계층적 (Hierarchical) 표현 기법을 설명하고, 브라우저가 제공하는 기본 삼차원 관찰 기능 외에 인체 뼈를 절단하는 기능과 삼차원 한글, 한자, 영문 텍스트 저작기능을 설명한다. 다른 하나는 가상 건축 설계 시스템으로 이차원 도면 설계 프로그램과 서버로 구성하여 건물, 건축 형식의 이차원 도면을 작성하여 전송하면 서버에서 삼차원 건축물을 생성하여 제공하는 시스템 개발 방법을 기술한다. 이차원 도면 설계 프로그램의 객체 지향 구현 기법과 클라이언트 (Client)와 서버 (Server) 간의 통신 및 인터페이스 (Interface) 릎 구현하여, 이차원 도변을 작성하여 그에 대한 결과를 전송 하는 방법에 대하여 논한다. 인체 골격 교육 시스템은 인터넷을 통한 교육 및 의료 활용에 실제감 있는 서비스를 제공하게 되고, 가상 건축 설계 시스템으로 원거리에서도 쉽게 건축 설계 결과를 평가하여 활용할 수 있을 것이다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.25-31
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• 2014

In this paper, a modified Alford loop antenna for on-body communication system is proposed. The proposed antenna operating in the ISM band is designed with consideration of human body effect. One of advantages of the Alford loop antenna structure is low-profile, however the Alford loop antenna is not suitable for on-body devices since it does not have a ground plane for other electronic part of on-body system and requires balanced feeding structure. To be embedded on on-body devices, the proposed antenna is design with the unbalanced feed structure and ground. The performance of the proposed antenna is simulated and measured when it is placed on the human body phantom to consider the effect of the human body. The proposed antenna a 10 dB return loss bandwidth over the ISM band and monopole-like radiation pattern with low-profile. The antenna has the surface of appropriate for on-body communication environment.

• Journal of IKEEE
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• v.26 no.1
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• pp.36-42
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• 2022

This study presents an analysis of the human body channel as an electric signal path using body impulse response (BIR). The human body communications (HBC) has recently emerged as an effective signal transmission method to create wireless body area networks (WBAN). We provide body channel characteristics based on measured BIR in a proper experimental environment for the HBC using capacitive coupling with a customized channel sounding device, which can be applied as a guideline for the HBC system design. The frequency response of the BIR, extracted by a customized signal processing for the measure signals, shows the channel path loss (CPS) between 0 MHz and 100 MHz with an average CPS of approximately 46.8 dB. In addition, the relative noise power distributions can provide estimations on the signal to noise ratio at the HBC receiver in terms of capacitor and resistor values in the measured frequency band and the frequency band lower than 3 MHz considering the baseband signal detection.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.6
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• pp.197-204
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• 2015

Recent changes in health care environment including aging population and prevalence of chronic disease encourage the adoption of new innovative technological solutions including wearable vital sensors, wireless networks, and smart phone. In this paper, we present an effective at-home lifestyle monitoring system that can be used for self-management and health intervention of patient himself in the Management-by-Exception perspectives. We implemented the filtering and queuing algorithms as a preprocessor of monitoring system to enhance efficiency of proposed system, and the effective UX design for self-management of patients themselves. The 94,467 actual clinic data was used to test the efficiency of the proposed system. As as a result, 64.8% of the incoming vital data was identified to be filtered out.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5A
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• pp.440-446
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• 2010

Convergence of IT and BT is considered in many area, especially in medical care industry. The example of this trend is a capsule endoscope. But in a capsule endoscope, communication through human body has a few restrictions. At first, the transmit power should be limited not to have a bad effect on human organs and for the battery capacity. Second, the channel characteristic of human body has not been examined exactly. Third, general modulation / demodulation techniques which require a channel estimation cannot be used because of battery limit. There also may be a lot of interference signals because a capsule endoscope uses UWB bandwidth. In this paper, we introduce Chirp Spread Spectrum Differential Binary Phase Shift Keying(CSS-DBPSK) and propose Chirp Spread Spectrum On-Off Keying(CSS-OOK) which don't require a channel estimation and robust to interference signals. Using CSS-DBPSK or CSS-OOK, we can get 5 dB or 2~3 dB of Eb/N0 gain at 10-5 target BER. And if there are interference signals, those gains of CSS-DBPSK and CSS-OOK are increased.

• Journal of Korea Multimedia Society
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• v.15 no.10
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• pp.1228-1235
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• 2012

In this Paper, we propose an energy efficient localization technique based on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for Wearable Computer systems. For this purpose, the proposed localization algorithm minimizes power consumption and estimates location without range information. It is executed independently on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. And it minimizes power consumption by estimating locations of sensor nodes with range-free method fast.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.16-23
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• 2015

In this paper, a bent microstrip patch antenna, which is suitable for band-type wearable devices and RF configuration, to be used in the WCDMA2100 mobile network is proposed. The proposed antenna using RF configuration which is consisted of separated Tx and Rx frequency band is designed to operate or function in WCDMA2100 Tx frequency band only and it is not strongly affected by the human body because of the conductor at the bottom side. At both flat case and bent case, the proposed antenna's maximum gain satisfies at least 5.3 dBi, and its -6 dB return loss bandwidth is wider than 20 MHz. The simulated surface absorption rate($SAR_{1g}$) result is under 0.7 [W/kg]. The proposed antenna suits in band-type wearable devices which is worn on wrists or arms.