• 한국전기전자재료학회논문지
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• 제22권3호
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• pp.222-229
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• 2009

A noble infrared sensor was studied for passenger conditional detection in vehicle, This research relates to uncooled infrared sensors for detecting the presence, type and temperature of occupants in vehicle. It sense that the occupants purpose to control the smart airbag for safety in the case of adult or child and to control the automatic air conditioning for convenience. This paper described the design and the fabrication of microbolometers which were composed of 2 by 8 elements using the surface micromachining technology. The characteristics of the array were investigated in the spectral region of $8{\sim}12{\mu}m$. The fabricated detectors exhibited the thermal mass of $7.05{\times}10^{-9}\;J/K$, the thermal conductance of $1.03{\times}10^{-6}\;W/K$, the thermal time constant of 6.8 ms, the responsivity of $2.96{\times}10^4\;V/W$ and the detectivity of $1.01{\times}10^9\;cmHz^{1/2}/W$, at the chopper frequency of 10 Hz and the bias current of $4.4{\mu}A$. We could successfully detect the human body condition in the divided zone. As a results, we concluded that microbolometer optimized in this research could be useful for the application of passenger conditional detection in vehicle.

• 전력전자학회논문지
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• 제9권2호
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• pp.163-170
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• 2004

1960년도부터 컨테이너를 사용한 해상 물동량이 급격히 증가되어 부두에서 처리하여야할 컨테이너 양이 많이 증가되었다. 부두의 운용효율을 증가시키기 위하여 야드 크레인의 정확히 위치 검출이 상당히 중요한 과제이다. 본 논문에서는 엔코더 출력펄스와 적외선센서를 사용하여 정확하고 신속하게 크레인의 절대위치를 측정하는 기법을 제시하였다. 갠추리 바퀴에 직결된 엔코더 펄스를 카운팅하여 갠추리의 이동거리를 측정한 후, 바퀴의 슬립 통에 인하여 발생하는 측정오차를 보상하기 위하여 적외선센서를 사용하였다. 실제 크레인의 1/10 축소한 시뮬레이터로 실험을 수행하여 본 논문에서 제시한 기법의 타당성을 확인하였다.

• 센서학회지
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• 제23권3호
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• pp.165-169
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• 2014

An existing infrared (IR) analysis system is generally composed of infrared source, IR focusing lenses, IR detector, and optical chopper. An optical chopper is widely used in combination with lock-in amplifier to improve the signal-to-noise ratio by periodically interrupting incident light beam. During recent years, a few researches on miniaturized optical chopper have been reported to apply to micro-scaled optical systems. In this paper, a micro optical chopper operated by electromagnetic actuation is proposed and applied to a miniaturized micro-scaled optical system operating in IR spectral range. Additionally, the fabrication method of the proposed micro chopper is demonstrated. The proposed micro optical chopper is composed of the polydimethylsiloxane (PDMS) membrane, solenoid, and permanent magnet. The permanent magnet is bonded on the PDMS membrane using an ultraviolet-activated adhesive. The operation of the chopper is based on the attractive and repulsive forces between permanent magnet and solenoid induced by an electrical current flowing through the solenoid. The fabricated micro optical chopper could operate up to 200 Hz of frequency. The maximum operating distance of the chopper with 7mm diameter membrane was $750{\mu}m$ at 100 Hz of frequency.

• 한국세라믹학회지
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• 제54권5호
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• pp.349-365
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• 2017

Graphene has attracted a lot of attentions due to the unique electrical and optical properties. Compared with the noble metal plasmons in the visible and near-infrared frequencies, graphene can support surface plasmons in the lower frequencies of terahertz and mid-infrared and it demonstrates an extremely large confinement at the surface because of the particular electronic band structures. Especially, the surface conductivity of graphene can be tuned by either chemical doping or electrostatic gating. These features make graphene a promising candidate for plasmonics, biosensing and transformation optics. Furthermore, the combination of graphene and metasurfaces presents a powerful tunability for exotic electromagnetic properties, where the metasurfaces with the highly-localized fields offer a platform to enhance the interaction between the incident light and graphene and facilitate a deep modulation. In this paper, we provide an overview of the key properties of graphene, such as the surface conductivity, the propagating surface plasmon polaritons, and the localized surface plasmons, and the hybrid graphene/metasurfaces, either metallic and dielectric metasurfaces, from terahertz to near-infrared frequencies. Finally, there is a discussion for the current challenges and future goals.

• 한국인터넷방송통신학회논문지
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• 제11권4호
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• pp.31-38
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• 2011

본 논문에서는 실내 전력소모를 효율적으로 줄이기 위하여, 무선센서네트워크 기반의 자율 실내조명 제어 시스템을 제안한다. 제안된 시스템에서는 먼저 출입문에 부착된 수동 적외선 (Passive Infrared: PIR) 센서를 이용하여 각 출입문을 통해 실내로 들어오고 나아가는 사람 수를 감지하다. 각 출입문에서 측정된 센서 값들은 무선센서네트워크를 통해 중앙 제어장치로 전송된다. 중앙제어장치는 전송된 센서 값을 이용하여 실내에 사람의 존재 유무를 파악할 수 있는 제어 알고리즘을 통해 실내조명을 자율적으로 제어 한다. 비용분석 및 시뮬레이션을 통해 제안된 시스템이 일상생활에 적용될 경우 약 20%의 전기소모를 절약할 수 있음을 보였다.

• 융합신호처리학회논문지
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• 제3권4호
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• pp.74-78
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• 2002

인체감지용 초전형 적외선 센서 시스템은 최소 2개 이상의 센서를 사용한다. 상부전극과 바닥전극의 디자인을 새로이 하여 센서 2개가 인체감지를 가능하게 하는 센서 시스템을 센서 1개로 구성한 변환기를 설계하였다. 초전성 효과를 나타내는 재료로는 P(VDF/TrFE) 필름을 이용하였다 제작된 적외선 센서는 기존의 2개 이상의 센서를 사용하던 시스템에 비해 거의 같은 결과인 적외선원 13 $\times$ 10$10^-6$ 에 대하여 9.62 $\times$ 10$10^5$ V/W 의 높은 전압감도를 나타내었으며 NEP (noise equivalent power) 는 3.95 $\times$ $10^-7$/ W, 그리고 specific detectivity D$^*$는 5.06 $\times$ $10^5$ cm/W나타내었다.

• 한국전기전자재료학회논문지
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• 제21권11호
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• pp.1005-1009
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• 2008

A noble infrared $\lambda/4$ absorbing structure using metal reflector was studied for uncooled infrared sensors. This paper described the design and the fabrication of IR uncooled detectors which were composed of 21 by 21 elements using the surface micromachining technology. The characteristics of the array were investigated in the spectral region of 4.26 ${\mu}m$. The fabricated detectors exhibited the thermal mass of $9.75\times10^{-9}$ J/K, the thermal conductance of $1.31\times10^{-6}$ W/K, the thermal time constant of 7.4 ms, the responsivity of $1.07\times10^5$ V/W and the detectivity of $1.04\times10^9$ $cmHz^{1/2}/W$, at the chopper frequency of 10 Hz and the bias current of 9.22${\mu}A$. Finally the absorptance efficiency of $\lambda/4$ absorbing structure was about 23.2 % higher than that of absence absorbing structure.

• 센서학회지
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• 제27권6호
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• pp.357-361
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• 2018

This paper presents an averaging current adjustment technique for reducing the pixel resistance variation in a bolometer-type uncooled infrared image sensor. Each unit pixel was composed of an active pixel, a reference pixel for the averaging current adjustment technique, and a calibration circuit. The reference pixel was integrated with a polysilicon resistor using a standard complementary metal-oxide-semiconductor (CMOS) process, and the active pixel was applied from outside of the chip. The averaging current adjustment technique was designed by using the reference pixel. The entire circuit was implemented on a chip that was composed of a reference pixel array for the averaging current adjustment technique, a calibration circuit, and readout circuits. The proposed reference pixel array for the averaging current adjustment technique, calibration circuit, and readout circuit were designed and fabricated by a $0.35-{\mu}m$ standard CMOS process.

• 센서학회지
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• 제30권3호
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• pp.148-153
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• 2021

During the manufacture of a ZnS lens with excellent transmittance in the mid-infrared region (3-5 ㎛) by the hot-press process, a single-layer sintering method is used in which one lens is manufactured in one process. Additional research is required to improve this single-layer sintering method because of its low manufacturing efficiency. To solve this problem, the variation in optical properties of ZnS lenses with change in sintering temperature was investigated by introducing a Stack sintering method that can sinter multiple lenses simultaneously. A carbon paper was placed between the molded lenses and sintered into five layers. The average permeability of 67% at medium infrared wavelengths of 3-5 ㎛ was excellent under the following sintering conditions: pressure of 50 MPa and temperature of 850℃. This value is 1% less than the average permeability in the case of single-layer sintering of the ZnS lens. It was confirmed that the stack sintering method developed in this study can be used to manufacture a large number of lenses with excellent characteristics in a single process.

• Structural Monitoring and Maintenance
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• 제9권3호
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• pp.259-270
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• 2022

This study explores the use of the recently developed "strain-sensing smart skin" (S⁴) method for noncontact strain measurements on cement-based samples. S⁴ sensors are single-wall carbon nanotubes dilutely embedded in thin polymer films. Strains transmitted to the nanotubes cause systematic shifts in their near-infrared fluorescence spectra, which are analyzed to deduce local strain values. It is found that with cement-based materials, this method is hampered by spectral interference from structured near-infrared cement luminescence. However, application of an opaque blocking layer between the specimen surface and the nanotube sensing film enables interference-free strain measurements. Tests were performed on cement, mortar, and concrete specimens with such modified S⁴ coatings. When specimens were subjected to uniaxial compressive stress, the spectral peak separations varied linearly and predictably with induced strain. These results demonstrate that S⁴ is a promising emerging technology for measuring strains down to ca. 30 𝜇𝜀 in concrete structures.