• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.6
• /
• pp.684-689
• /
• 2017

We examined the possibility of developing an early monitoring system using the shell valve movement activity of Pacific oyster (Crassostrea gigas) for early detection of low salinity water in coastal areas. At salinity levels of 30 psu and 20 psu, SVMs were detected $7.32{\pm}3.21times/hr$ and $7.11{\pm}3.90times/hr$, respectively, The patterns and times of SVMs were not significantly different between the two experiment phases. However, at 10 psu and 5 psu, shell valves were observed to be permanently closed in all experiments. Under combined condition (Group 1: temperature $15^{\circ}C$ ${\times}$ salinity 15 psu), SVMs were observed from 20 psu to 30 psu over a 2 - 3 hr period, and then remained closed. In Group 2 (temperature $30^{\circ}C$ ${\times}$ salinity 15 psu), SVMs were observed, which indicated that the physiological condition of the oysters reached a critical point. Thus, it may be possible to utilize SVMs as an early warning signal for low salinity water.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.11
• /
• pp.1075-1081
• /
• 2004

In this paper, a VCO of a general advance warning system for vehicle's speed limitation in the X-band used in Japan is designed using a small signal scattering coefficient of PHEMT. A varactor diode that wide tuning range and series resistance 0 H is used for designing the VCO and -85 dBc/Hz of phase noise at 10 kHz of offset frequency is obtained by adjusting the reflection coefficient between the micro-strip line and the varactor device which determines transistor's operation voltage and resonant frequency, In addition +4.5 dBm of basic frequency signal output level and -25.6 dEc of the second harmonic constraint are acquired. Sample that produce in this paper could confirm that more excellent special quality appears than existing products in sensitivity.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.39-40
• /
• 2011

본 논문에서는 포토커플러와 DC모터를 이용한 축소형 자동운전 에스컬레이터를 제작한다. 포토커플러는 전기신호를 빛으로 변환하고 그 빛을 다시 전기신호로 전환하는 회로패스이다. 이 축소형 자동운전 에스컬레이터에는 3개의 포토커플러가 사용이 되고 입구에 하나 출구에 두개를 사용하여 입구의 포토커플러가 켜지면 운행이 되고 출구의 두개의 포토커플러 중 2번 포토커플러가 켜지면 안전을 위해 경보음이 울리게 한다. 여기서 에스컬레이터 양축의 힘의 평형을 위해 두개의 DC모터를 사용해 제작하게 된다. 이 축소형 자동 에스컬레이터는 광센서를 이용하여 전기절약과 안전을 생각한다. 직접 제작을 통해 에스컬레이터가 계속 켜져 있지 않고 필요할 때 켜지게 되므로 전기절약이 되고 경보음으로 인해 안전에 유의할 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.9
• /
• pp.1793-1798
• /
• 2007

Recently there are some trends to construct smart home system infrastructure depending upon the development of Information and Communication Technology. Also requirements of the Ubiquitous Healthcare Systems at home which can monitor the status of health continuously are increased rapidly comparing with hospitals. Healthcare service can be divided into two categories. The first one is Alarm Service that can be used for the emergency status and the other one is Remote Support Service which can monitor the patient including home environments and give those diagnosis information to medical office or to his family. Generally wired networks and fixed healthcare measuring system have some limits to transmit reliable realtime based information for both categories described above comparing with portable monitoring system. Getting over the inefficiency we will design and implement portable healthcare system under the wireless Zigbee network environments.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2010.04a
• /
• pp.510-515
• /
• 2010

이 논문은 주택 및 영세사업장의 모의설비 시스템을 구성하여 전기화재원인 분석 및 이상신호 검출이 가능한 하드웨어 개발과 소프트웨어 개발이 주목표이다. 이를 위하여 주택 및 영세사업장 현장실태 조사를 통하여 모의설비 시스템을 구성하고 개발된 하드웨어와 소프트웨어를 정착하여 전압 및 전류에 대한 각각의 정상 및 이상신호를 분석하였다. 본 연구에서 제안한 전기화재 신호 분석용 시스템을 통하여 전기화재 감지장치의 기준값 설정과 전기재해 취약장소에 설치하여 전기화재를 조기에 경보하여 국민의 인적 물적 재산상의 손실을 방지할 수 있을 것으로 판단된다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.4
• /
• pp.759-765
• /
• 2000

A diagnosis system that provides early warnings regarding machine malfunction is very important for rolling mill so as to avoid great losses resulting from unexpected shutdown of the production line. But it is very difficult to provide early warnings in rolling mill. Because dynamics of rolling mill is non-linear. This paper shows a chaotic behavior of vibration signal in rolling mill using embedding method. Not only phase plane and Poincare map are implemented but also FH and histogram of vibration signal in rolling mill is presented by embedding method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.10a
• /
• pp.5-7
• /
• 2012

선교에는 항해사에게 정보를 전달하기 위하여 다양한 신호가 존재한다. 항해 및 통신 장비로부터 나오는 음향 신호 등 다양한 청각 신호들이 존재하지만 이러한 청각 신호, 청각 경고음에 대한 인간의 인지능력에 관한 연구는 미흡한 실정이다. 청각 경고음은 크게 음성(speech), 함축적 소리(abstract sound), 청각 아이콘(auditory icon)으로 구분 할 수 있다. 본 연구에서는 청각 경고음 중 청각아이콘을 활용하여 5가지의 경보상황(엔진, 화재, 조타, 전기, 충돌)에서 청각아이콘에 대한 감성평가를 통해 각 상황에 적합한 청각아이콘을 선별하였다. 본 연구 결과는 선교 내 청각표시장치와 통합선교알람관리시스템을 위한 기초자료로 활용될 수 있을 것으로 기대된다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.732-735
• /
• 2012

본 논문은 지상에서 발생하는 전자파 잡음 신호의 유입에 의해 많은 영향을 받을 수 있는 헬기 등 항공기의 레이더경보수신기(Radar Warning Receiver)에서도 레이더 펄스 신호를 탐지할 수 있는 통신전자파잡음 동적제거 기법을 제안하였다. 본 논문은 지상의 노이즈 신호를 분류하는 방법을 제시하였고, 노이즈 신호 레벨을 판단하여 효과적으로 잡음을 제거하는 알고리즘을 제안하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.890-893
• /
• 2014

In this paper, we present a signal processing algorithm for a marine radar system, in which the evaluation of probability of collision as well as target detection and tracking are performed. Moreover, the digital signal processor that implements the algorithm is proposed. As simulation environment, a mechanically scanning antenna utilizing FMCW signal is used, conducting the beamforming operation with 1 degrees intervals. Test board consists of DSP chips and FPGA, which enable the implemented system to operate in real-time.

• Journal of the Korean Geographical Society
• /
• v.46 no.6
• /
• pp.738-750
• /
• 2011

Partly due to the climate changes, flooding occurs more often than before. Particularly high urbanization causes more damages by flooding with unexpected downpours. Recent mobile telecommunication technology can help to reduce the damage by a natural disaster with quick alarming process. This research aimed to implement a flood warning GIS service system based on open source software and mobile hybrid application program with LBS. The developed system utilized location information of mobile clients for smart phone users to get alerted to flooding immediately. This service system would be very useful in urban areas to reduce the flood damages.