• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1933-1934
• /
• 2008

네트워크 통신(network communication)을 위해서는 개별 정보가전기기의 전원인가 상태가 상시 유지되어야 하는 문제점을 가지고 있다. 이러한 문제를 극복하기 위해, 통신요청시에는 그 때마다 통신동작이 가능하도록 충분한 전력공급을 제공하는 절대조건을 만족시키는 반면, 통신대기시에는 최소한의 전력만이 공급됨으로서 해서 초절전을 실현할 수 있는 정보가전기기의 PLC통신모듈용 전원장치를 먼저 개발하였다. 그리고, 최근 절전이 강조되고 있은 시점에서, 제품자체의 절전기능이 포함되어 전기에너지를 절약할 수도 있지만, 사용자의 절전의지와 행위에 의해서도 전기에너지를 절약할 수 있다. 이러한 관점에서 볼때 본 연구개발에서는, 제품의 전원플러그를 콘센트에 꽂는 과정에서 콘센트와 전원플러그 사이에 전기에너지량을 계측할 수 있는 전자회로 및 계측값을 나타내는 표시장치 그리고 필요에 따라서 통신기능을 포함하는 전기콘센트 단위의 Electric Energy Metering Sensor(이하 EEMS) 모듈을 개발하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.2
• /
• pp.550-565
• /
• 2018

Cognitive radio technology is still the key technology of future mobile communication systems. Previous studies have focused on improving spectrum utilization and less energy consumption. In this paper, we propose an Overhead Reduced Scheme (ORS) for green cooperative spectrum sensing. Compared to traditional cooperative sensing scheme, ORS scheme divides the sensing time into three time slots and selects the best multi-mode user to report decisions. In consideration of reporting channel deviation, we derive closed-form expressions for detection probability and false alarm probability of ORS scheme based on Rayleigh fading channel. Simulation results show that ORS scheme can improve the perception accuracy while reducing the perceived delay and energy consumption in the process of perception, so as to realize the green communication.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.11 no.1
• /
• pp.226-230
• /
• 1989

As carotid-cavernous fistula is the major complication that can be occurred uncommonly after maxillofacial injuries, it is abnormal arteriovenous communication between cavernous sinus and internal carotid artery. Such an arteriovenous communication is most often the result of injuries, but need not be associated with bony fracture. It usually begins soon after an injury, but it may be delayed for as long as several months. It begins undramatically with eye pain, headache and slow protrusion of eye ball. A bruit may be heard above the eye with stethoscope. Close examination will reveal dilatation of superficial veins of the eyelid and forehead and periorbital edema. There will be complete or partial ophthalmoplesia of the affected eye. Compression of the common carotid artery on the ipsilateral side will reduce or obliterate the bruit. The lesion in the cavernous sinus is them demonstrable by angiography.