• 한국광학회지
• /
• 제8권5호
• /
• pp.415-419
• /
• 1997

광섬유 격자는 외부의 가해진 물리량에 대해 선형적인 응답을 하며, 광섬유 격자의 파장 인코딩 특성으로 인해 S/N비가 높은 신호 처리를 할 수 있는 장점이 있다. 본 논문에서는 편광 유지 광섬유 격자를 이용한 압력 센서에 관한 실험을 수행하였다. 편광 유지 광섬유 격자는 위상 마스크를 이용하여 Bow-Tie형 광섬유에 형성시켰는데, 편광 유지 광섬유는 두 개의 고유 편광 축을 가지므로 두 개의 브래그 peak을 가진다. 종방향 스트레인과 온도 변화에 따른 두 개의 브래그 파장 변화를 측정한 결과 각각 1.2 pm/.mu..epsilon.의 종방향 스트레인에 대한 파장 민감도와 11.4 pm/.deg. C의 온도에 대한 파장 민감도가 관측되어, 단일 모드 광섬유 격자의 보고된 값과 거의 일치하였다. 반면에 편광 유지 광섬유 격자에 횡방향 스트레스를 가하면 두 브래그 파장사이의 간격이 변화함을 관측하였고, 두 브래그 파장 간격에 대하여는 14.6 pm/N의 횡방향 스트레스에 대한 파장 민감도를 얻었다. 편광 유지 광섬유 격자 센서는 온도의 변화에 무관한 횡방향 스트레스 즉, 압력센서로 이용할 수 있음을 보였다.

• 한국군사과학기술학회지
• /
• 제6권4호
• /
• pp.22-28
• /
• 2003

In the conventional weapon system, such as gun and small arms, it Is a general trend that for maximization of its performance and enhancement of its effectiveness, the firing control system(FCS) is developed and applied with the guns and small arms in the world. The FCS of the small arms for infantry man is composed of a few of sensors for acquisition of input data of FCS, such as range measurement, position sensing of weapon, temperature, etc., computer, displayer and power pack, and also the air burst munition is developed in parallel for the maximization of FCS's effectiveness. Since the flight time setting fuze for the air burst munition is adapted for next me, the measuring device of the muzzle velocity is needed to overcome the variation of muzzle velocity due to producing procedures and the differences of the using temperatures and so maintain the burst position accuracy This paper contained the technical information on the development of the measuring device of muzzle velocity, which designed in compact & light weight configuration with reliability and accuracy.

• 한국전산구조공학회논문집
• /
• 제37권2호
• /
• pp.95-101
• /
• 2024

본 논문에서는 다이나믹크리깅 대리모델 기반 자동차 브레이크 패드 마모량 측정센서 브라켓의 설계최적화를 소개한다. 브레이크 작동시 마찰재 바닥의 온도가 600℃ 이상으로 상승하고, 이 열이 전달되어 센서의 기능을 상실시킨다. 따라서 열전달을 최소화하는 브라켓 형상의 설계최적화는 필수적이다. 최적화에 소요되는 계산비용을 절감하기 위해 다이나믹크리깅 대리모델로 열전달 시뮬레이션을 대체하였다. 다이나믹크리깅은 최적의 상관함수와 기저함수를 선정하였으며, 정확한 대리모델을 도출하였다. 최적화 결과 센서위치의 온도가 초기모델에 비해 7.57% 감소하였으며, 이를 열전달 시뮬레이션으로 다시 한번 확인하여 대리모델 기반 최적설계가 유의미함을 검증하였다.

• 산업기술연구
• /
• 제28권B호
• /
• pp.39-45
• /
• 2008

Temperature variation according to space and time on the inner parts of engineering constructions(e.g.: dam, slope) can be a basic information for diagnosing their safety problem. In general, as constructions become superannuated, structural deformation(e.g.: cracks, defects) could be occurred by various factors. Seepage or leakage of water through these cracks or defects in old dams will directly cause temperature anomaly. Groundwater level also can be easily observed by abrupt change of temperature on the level. This study shows that the position of seepage or leakage in dam body can be detected by multi-channel temperature monitoring using thermal line sensor. For this, diverse temperature monitoring experiments for a leakage physical model were performed in the laboratory. In field application of an old earth fill dam, temperature variations for water depth and for inner parts of boreholes located at downstream slope were measured. Temperature monitoring results for a long time at the bottom of downstream slope of the dam showed the possibility that temperature monitoring can provide the synthetic information about flowing path and quantity of seepage of leakage in dam body.

• 한국인터넷방송통신학회논문지
• /
• 제13권4호
• /
• pp.221-227
• /
• 2013

본 논문에서는 제로 에너지 하우스의 에너지 절감을 모니터링하기 위하여 Zigbee 통신을 이용한 온 습도, 연기감지, 조도 및 CO2의 복합 센서 보드를 개발하고 이를 처리하는 프로토콜 등에 관하여 다루었다. 특히 센서를 장착시키는 실내 공간의 위치에 따라 제어하는 알고리즘이 달라지게 되므로 이를 무선인 Zigbee를 통하여 센서 장착 위치를 자유롭게 변경할 수 있다는 장점이 있으며. 또한 창을 통해 발생하는 에너지 손실을 줄일 수 있고 실내의 조명 제어에도 중요한 역할을 할 수 있는 시스템이다.

• 한국항행학회논문지
• /
• 제18권1호
• /
• pp.56-66
• /
• 2014

태양광 발전에 있어서 태양전지는 일사량, 온도와 부하에 의해 크게 변동하기 때문에 태양전지에 대한 특성 해석이 필요하다. 또한 태양광 발전에 있어서 가능한 많은 에너지를 얻기 위해서는 환경변화에 따른 태양의 위치추적이 필요하며 태양전지의 출력을 항상 최대로 제어할 필요가 있다. 센서와 마이크로프로세서 칩으로 구현된 본 시스템의 실험 결과는 Boost 컨버터의 승압율은 167[%], 소용량에서 에너지 Harvesting 개념과 위치추적 방식의 태양광 발전 구현 가능성을 제시하였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 춘계학술대회 논문집
• /
• pp.948-951
• /
• 2008

Ubiquitous sensor network (USN) based on ZigBee communication protocol has been used in various application fields, such as home-network, intelligent building and machine, logistics, environmental monitoring, military field, security field and etc. The ZigBee is targeted at radio-frequency application that require a low data rate, long battery life and secure network. Especially, the USN system can be applied efficiently to building-indoor where the complex geometry is adopted. In this study, all 90 points of railway cabin indoor were monitored for temperature and humidity using USN technology. All sensors were pre/post-calibrated and the temperature/humidity change were analyzed in a railway cabin in real-time. The results would be useful to develop the cabin heating, ventilating and air conditing (HVAC) system to meet all passengers' thermal comfort regardless of their seat position.

• 한국전문물리치료학회지
• /
• 제12권2호
• /
• pp.1-10
• /
• 2005

Pressure ulcers are serious complications of tissue damage that can develop in patients with diminished pain sensation and diminished mobility. Pressure ulcers can result in irreversible tissue damage caused by ischemia resulting from external loading. There are many intrinsic and extrinsic contributors to the problem, including interface tissue pressure, shear, temperature, moisture, hygiene, nutrition, tissue tolerance, sensory and motor dysfunction, disease and infection, posture, and body support systems. The purposes of this study were to investigate the relationship between buttock interface pressure and seating position, wheelchair propulsion speed. Seated-interface pressure was measured using the Force Sensing Array pressure mapping system. Twenty subjects propelled wheelchair handrim on a motor-driven treadmill at different velocities (40, 60, 80 m/min) and seating position used recline ($100^{\circ}$, $110^{\circ}$, $120^{\circ}$) with a wheelchair simulator. Interface pressure consists of average (mean of the pressure sensor values) and maximum pressure (highest individual sensor value). The results of this study were as follows; No significant correlation in maximum/average pressure was found between a static position and a 40 m/min wheelchair propulsion (p>.05). However, a significant increase in maximum/average pressure were identified between conditions of a static position and 60 m/min, and 80 m/min wheelchair propulsion (p<.05). No significant correlation in maximum pressure were found between a $90^{\circ}$ recline (neutral position) and a $100^{\circ}$, $110^{\circ}$, or $120^{\circ}$ recline of the wheelchair back (p>.05). No significant difference in average pressure was found between conditions of a $90^{\circ}$ recline and both a $100^{\circ}$ and $110^{\circ}$ recline of wheelchair back. However, a significant reduction in average pressure was identified between conditions of a $90^{\circ}$ and $120^{\circ}$ recline of wheelchair back (p<.05). This study has shown some interesting results that reclining the seat by $120^{\circ}$ reduced average interface pressure, including the reduction or prevention in edema. And interface pressure was greater during dynamic wheelchair propulsion compared with static seating. Therefore, the optimal seating position and seating system ought to provide postural control and pressure relief. We need an education on optimal seating position and a suitable propulsion speeds for wheelchair users.

• 한국태양에너지학회 논문집
• /
• 제21권4호
• /
• pp.55-62
• /
• 2001

A parabolic dish concentrator used in a high temperature application of solar energy tracks the sun's movement by two axis sun tracking system. In such a system, sun tracking performance affects the system efficiency directly. Generally the higher the tracking accuracy is, the better the system performance is. A large number of parabolic dish type concentrators has been developed and implemented in the world. However none of them clearly provided a qualitative method of how the accuracy of the sun tracking system can be evaluated. The work presented here is the evaluation of sun tracking performance of parabolic dish concentrator, which follows the sun's movement by the sensor, using a computer vision system. We install a camera on the parabolic dish concentrator. While the concentrator follows the sun, sun's images are captured continuously. Then the performance of sun tracking system was evaluated by analyzing the variation of the position of the sun in the captured images.

• Journal of Advanced Marine Engineering and Technology
• /
• 제25권3호
• /
• pp.644-654
• /
• 2001

In this paper, an electronic control unit of the automobile engine for optimal fuel injection an spark timing control has been designed and developed. This system includes hardware and software for a precise control of fuel injection and ignition timing. Especially, the crank angle sensor provides two separate signals: One is the position signal (POS) which indicates 180 degree pulses per revolution, and the other is the reference signal (REF) that represents each cylinder individually. Consequently, the developed engine control system has been able to control fuel injection and ignition timing more quickly and accurately. Through the experiment, it has been found that the fuel injection duration and the position of MBT have been influenced by coolant temperature, air flow rate and engine speed.