• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.114-117
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• 2011

A thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated and then thin 1.6 ${\mu}m$ thickness P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated also. These thick and thin P(VDF/TrFE) film pyroelectric infrared ray sensor was mounted in TO-5 housing to detect infrared light of 5.5 ~ 14 ${\mu}m$ wavelength for human body detecting with each other. The noise output voltage of the thick P(VDF/TrFE) film pyroelectric infrared ray sensor were 380 mV and NEP(noise equivalent power) is $3.95{\times}10^{-7}$ W which is the similar value with the commercial pyroelectric infrared ray sensor using ceramic materials as a sensing material. The NEP and specific detectivity $D^*$ of the thin P(VDF/TrFE) film pyroelectric infrared ray sensor were $2.13{\times}10^{-8}$ W and $9.37{\times}106$ cm/W under emission energy of 13 ${\mu}W/cm^2$ respectively. These result caused by lower thermal diffusion coefficient of a thin 1.6 ${\mu}m$ thickness PVDF/TrFE film than the thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.138-143
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• 2008

RFID 기술은 기존의 바코드 기술보다 발전된 무선의 비접촉 인식 기술로서, 유비쿼터스 컴퓨팅의 핵심기술로 간주되고 있다. RFID 태그는 기존의 단순한 사물의 인식 기능 중심에서 사물의 상태 및 환경 정보를 감지할 수 있는 센서 태그로의 발전으로 물류 프로세스의 양적, 질적 향상을 도모할 수 있게 되었다. 센서 태그는 환경 정보를 센싱하기 위하여 배터리를 내장하고 있으며, RF Transceiver의 내장 유무에 따라 자체적으로 신호를 보낼 수 있는 active 센서 태그와 리더로부터의 신호를 사용하는 semi-passive 센서 태그로 구분된다. Semi-passive 센서 태그는 배터리를 부착함으로써 passive 태그에 비해 인식률과 인식거리가 향상되었고 active 태그에 비해 단가가 매우 저렴하여 센서 태그가 부착된 물품의 상태를 모니터링하고 환경을 감시하는 다양한 응용에 사용될 수 있다. 이러한 응용의 요구에 따라 Edge Manager는 기존의 passive 태그는 물론 센서 태그를 지원함으로써 상위 응용에게 정제된 결과를 전달할 필요성이 있다. 본 논문에서는 특히 semi-passive 센서 태그를 지원하는 Edge Manager의 설계를 위하여, 센서를 사용한 또 다른 활용 분야인 센서 네트워크에서의 질의 유형을 분석하고, semi-passive 센서 태그의 특징을 고려한 요구사항을 분석한다. Semi-passive 센서 태그는 센서 네트워크의 센서 노드와는 달리 태그 레벨에서 필터링과 병합을 수행할 수 없으므로 Edge Manager에서 이러한 기능이 제공되어야 한다. 본 논문에서는 Edge Manager에서의 센서 태그 데이터에 대한 질의를 위한 방법으로 EPCglobal ALE 표준명세의 ECSpec을 확장하는 방법을 제안하고, 센서 태그 데이터의 특성을 고려한 필터링 기법과 병합(aggregation) 기법을 적용한 질의 처리가 가능한 Edge Manager의 구조를 제시한다.

• Smart Structures and Systems
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• v.18 no.6
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• pp.1217-1231
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• 2016

In this research, a slotted patch antenna sensor is designed for wireless strain and crack sensing. An off-the-shelf RFID (radiofrequency identification) chip is adopted in the antenna sensor design for signal modulation. The operation power of the RFID chip is captured from wireless reader interrogation signal, so the sensor operation is completely battery-free (passive) and wireless. For strain and crack sensing of a structure, the antenna sensor is bonded on the structure surface like a regular strain gage. Since the antenna resonance frequency is directly related with antenna dimension, which deforms when strain occurs on the structural surface, the deformation/strain can be correlated with antenna resonance frequency shift measured by an RFID reader. The slotted patch antenna sensor performance is first evaluated through mechanics-electromagnetics coupled simulation. Extensive experiments are then conducted to validate the antenna sensor performance, including tensile and compressive strain sensing, wireless interrogation range, and fatigue crack sensing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.858-865
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• 2008

In this paper, Capacitive Telemetry RF Sensor System using Recursive Least Square (RLS) algorithm was proposed. General Telemetry RF Sensor System means that it should be "wireless", "implantable" and "batterless". Conventional Telemetry RF Sensor System adopts Integrated Circuit type, but there are many defects like complexity of structure and the limitation of large power consumption in some cases. In order to overcome these disadvantages, Telemetry RF Sensor System based on inductive coupling principle was proposed in this paper. Proposed Telemetry RF Sensor System is very simple because it consists of R, L and C and measures the changes of environment like pressure and humidity in the type of capacitive value. This system adopted RLS algorithm for estimation of this capacitive parameter. For the purpose of applying RLS algorithm, proposed system was mathematically modelled with phasor method and was quasi-linearized. As two parameters such as phase and amplitude of output voltage for estimation were needed, Phase Difference Detector and Amplitude Detector were proposed respectively which were implemented using TMS320C2812 made by Texas Instrument. Finally, It is verified that the capacitance of proposed telemetry RF Sensor System using RLS algorithm can be estimated efficiently under noisy environment.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.8
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• pp.104-109
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• 2019

Damage caused by wild animals such as pheasants and magpies is a problem in rural areas. A bird repellent system based on sensing and repelling farm pest animals and birds is proposed herein. This system is equipped with a bird model part on a supporting platform and comprises a sound source generator, a system control user interface, and a sensor in the center. The sensor is composed of an illuminance sensor and a PIR sensor. The illuminance sensor distinguishes between day and night, whereas the PIR sensor detects birds or wild animals and outputs them from the sound generator. The entire system can be managed easily by the user interface and system control.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.3
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• pp.333-340
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• 2015

In this paper, we propose a passive microwave sensor for detecting human body using microwave radiometer technologies. The proposed sensor detects human body by measuring the change of the received radiation power from fixed background object due to human body. A C-band microwave radiometer is designed and implemented. The received radiation power changes due to human body is measured by the C-band microwave radiometer, and the effectiveness of the proposed sensor is evaluated by the measurement result analysis.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.1
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• pp.9-15
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• 2012

This paper shows an effective scanning trajectory for a mine detection device that is one of the mission equipments of unmanned ground vehicle. The mine detection device is composed of a mine-detection sensor, and a 4 DOF manipulator enabling sensor position control. There are three modes that manage the mine detection device: passive, semi-automatic, and automatic. The automatic mode is used the most. This paper suggests a scanning method that makes shape of 8. This method prevents missing target area and enhances scanning speed when the mine detection device scans the ground surface in automatic mode. The suggested method is verified by simulations and experiments.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.12
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• pp.83-88
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• 1997

We present a fiber laser sensor that uses a fiber grating as a strain sensor head and an end-reflector of the laser cavity. A passive wavelength. The long-period grating band-rejection filter showed a wide usable filter wavelength range of about 25 nm, and the intensity of transmitted light increased by 16% for 1nm sensor wavelength shift in trhe measurement range.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.96-102
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• 2012

This paper addresses photometric distortion problems of a compact 3D scanning sensor which is composed of a micro-size and inexpensive camera-projector system. Recently, many micro-size cameras and projectors are available. However, erroneous 3D scanning results may arise due to the poor and nonlinear photometric properties of the sensors. This paper solves two inherent photometric distortions of the sensors. First, the response functions of both the camera and projector are derived from the least squares solutions of passive and active calibration, respectively. Second, vignetting correction of the vision camera is done by using a conventional method, however the projector vignetting is corrected by using the planar homography between the image planes of the projector and camera, respectively. Experimental results show that the proposed technique enhances the linear properties of the phase patterns that are generated by the sensor.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.469-472
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• 2023

If temperature management is required in factory or environmental monitoring, temperature can be measured by connecting various sensors wired or wirelessly. Surface acoustic wave sensors measure temperature using changes in acoustic waves on the sensor surface according to temperature, and are useful for wireless networks. In this paper, in order to build a wireless temperature measurement system in the 900 MHz frequency band, the temperature characteristics of the passive SAW sensor were measured, and the analysis and removal of multipath reflection wave effect inside the high temperature chamber were conducted. The resonant frequency of the SAW sensor was measured, and radio transmission/reception and multipath reflected wave removal techniques were proposed in the shielded chamber.