• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.11A
• /
• pp.1027-1034
• /
• 2005

IEEE802.15.4a, which is started to realize the PHY layer including high precision ranging/positioning and low data rate communication functions, requires a simple and low power consumable transceiver architecture. To satisfy this requirements, the simple noncoherent on-off keying (OOK) UWB transceiver with the parallel energy window banks (PEWB) giving high precision signal processing interface is proposed. The flexibility of the proposed system in multipath fading channel environments is acquired with the pulse and bit repetition method. To analyze the bit error rate (BER) performance of this proposed system, a noise model in receiver is derived with commonly used random variable distribution, chi-square. BER of $10^{-5}$ under the line-of-sight (LOS) residential channel is achieved with the integration time of 32 ns and signal to noise ratio (SNR) of 15.3 dB. For the non-line-of-sight (NLOS) outdoor channel, the integration time of 72 ns and SNR of 16.2 dB are needed. The integrated energy to total received energy (IRR) for the best BER performance is about $86\%$.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.11C
• /
• pp.1098-1105
• /
• 2009

In this paper, we propose an asynchronous UWB (Ultra Wide Band) Positioning scheme that can provide precise positioning performance with low complexity and low power consumption. We also present the residual test to improve the positioning performance in multipath channels having heavy NLoS (Non-Line of Sight) components. As compared to conventional ToA (Time of Arrival) positioning scheme that requires round-trip transmissions as many as the number of beacons, the proposed UWB positioning scheme effectively decrease power consumption and processing delay since a single round-trip transmission is only required. Also, as compared to conventional TDoA (Time Difference of Arrival) positioning scheme requiring precise synchronization among the beacons, asynchronous nature of the proposed scheme achieves very low system complexity. Through simulations in LoS (Line of Sight) channel models, we observe that the proposed scheme requires low system complexity, low power consumption, while providing positioning performance of almost the same accuracy as the conventional ToA and TDoA positioning schemes. In addition, the proposed scheme by employing the residual test achieves accurate positioning performance even in multipath channels having heavy NLoS components.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.12
• /
• pp.105-113
• /
• 2008

In Ubiquitous Society, accurate Location Calculation of user's device is required to achieve the need of users. As the location calculation is processed by ranging between transceivers, if some obstacles exist between transceivers, NLoS(Non-line-of-Sight) components of received signal increase along with the reduction of LoS(Line-of-Sight) components. Therefore the location calculation error will increase due to the NLoS effect. The conventional location calculation algorithm has the original ranging error because there is no transformation of ranging information which degrades the ranging accuracy. The Iterative Calculation method which minimizes the location calculation error relys on accurately identifying NLoS or LoS condition of the tested channel. We employ Kurtosis, Mean Excess Delay and RMS Delay spread of the received signal to identify whether the tested channel is LoS or NLoS firstly. Thereafter, to minimize location calculation error, the proposed Iterative Calculation method iteratively select random range and finds the averaged target location which has high probability. The simulation results confirm the enhancement of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.225-226
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.235-236
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.457-458
• /
• 2010

• 보건세계
• /
• v.63 no.1
• /
• pp.30-32
• /
• 2014

협회는 국민보건 사업의 일환으로 결핵 및 호흡기질환의 예방과 퇴치를 위해 홍보, 교육 사업은 물론 결핵예방접종 백신 및 감염진단 시약의 생산과 연구 등과 같은 다양한 사업을 수행해오고 있다. 그 가운데에서도 이번 호에서는 결핵 발견의 최전방에 선 검진팀의 일과를 소개하고자 한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 1988.10a
• /
• pp.148-153
• /
• 1988

In this study, the stabilization of moving sight using a gyro is investigated. At first, Linear Compensator was design by linearizing gyro, torque motor and several parameters from a given required frequency response curve. By using this, System Control Performance was analyzed by back EMF, torque saturation and Coulomb friction effects. Also stabilization Performance by disturbances and Paramter variations were simulated.

• IT SoC Magazine
• /
• s.13
• /
• pp.29-31
• /
• 2006

일본 동경 오다이바 Big Sight에서 지난 4월 5일부터 7일까지 사흘간 국제 센서 박람회가 개최되었다. 약 90여개사가 참여하여 가속도, 압력 센서 등을 선보였으며, 해외 센서 현황을 알아볼 수 있는 좋은 기회가 되었다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.135-136
• /
• 2007