• Title/Summary/Keyword: Chemical sensor

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The Classification Using Probabilistic Neural Network and Redundancy Reduction on Very Large Scaled Chemical Gas Sensor Array (대규모 가스 센서 어레이에서 중복도의 제거와 확률신경회로망을 이용한 분류)

  • Kim, Jeong-Do;Lim, Seung-Ju;Park, Sung-Dae;Byun, Hyung-Gi;Persaud, K.C.;Kim, Jung-Ju
    • Journal of Sensor Science and Technology
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    • v.22 no.2
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    • pp.162-173
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    • 2013
  • The purpose of this paper is to classify VOC gases by emulating the characteristics found in biological olfaction. For this purpose, we propose new signal processing method based a polymeric chemical sensor array consisting of 4096 sensors which is created by NEUROCHEM project. To remove unstable sensors generated in the manufacturing process of very large scaled chemical sensor array, we used discrete wavelet transformation and cosine similarity. And, to remove the supernumerary redundancy, we proposed the method of selecting candidates of representative sensor representing sensors with similar features by Fuzzy c-means algorithm. In addition, we proposed an improved algorithm for selecting representative sensors among candidates of representative sensors to better enhance classification ability. However, Classification for very large scaled sensor array has a great deal of time in process of learning because many sensors are used for learning though a redundancy is removed. Throughout experimental trials for classification, we confirmed the proposed method have an outstanding classification ability, at transient state as well as steady state.

Fabrication of Potentiometric Sodium-ion Sensor Based on Carbon and Silver Inks and its Electrochemical Characteristics (탄소 및 은 잉크 기반의 전위차 나트륨 이온 센서 제조 및 이의 전기화학적 특성)

  • Kim, Seo Jin;Son, Seon Gyu;Yoon, Jo Hee;Choi, Bong Gill
    • Applied Chemistry for Engineering
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    • v.32 no.4
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    • pp.456-460
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    • 2021
  • A potentiometric sodium-ion (Na+) sensor was prepared using a screen-printing process with carbon and silver inks. The two-electrode configuration of the sensor resulted in potential differences in Na+ solutions according to Nernstian equation. The obtained Na+-sensor exhibited an ideal Nernstian sensitivity, fast response time, and low limit of detection. The Nernstian response was stable when the sensor was tested for repeatability and long-term durability. The Na+-selective membrane coated onto the carbon electrode selectively passed sodium ions against interfering ions, indicating an excellent selectivity. The portable Na+-sensor was finally fabricated using a printed circuit system, demonstrating the successful measurements of Na+ concentrations in various real samples.

1,8-Naphthyridine Modified Naphthalimide Derivative: Ratiometric and Selective Sensor for Hg2+ in Organic Aqueous Solution

  • Shi, Yong Gang;Duan, Yu Lian;Chen, Jian Hua;Wu, Xiang Hua;Zhou, Ying;Zhang, Jun Feng
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.63-67
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    • 2013
  • A bottom-modified (4-position) naphthalimide derivative 1 with 1,8-naphthyridine as binding site has been designed and synthesized. Compound 1 is the first 1,8-naphthyridine-modified naphthalimide-based sensor that can detect $Hg^{2+}$ selectively with respect to ratiometric fluorescent change and blue shift in organic aqueous solution. The Job's plot and FAB mass indicate that 1 formed a 1:1 complex with $Hg^{2+}$. A top-modified naphthalimide derivative 2 with 1,8-naphthyridin as binding site has also been synthesized for comparison.

Integrated-optic sensors in glass (유리집적 광 센서)

  • 형창희;김종헌
    • Electrical & Electronic Materials
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    • v.9 no.5
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    • pp.518-525
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    • 1996
  • 본 고에서는 유리 집적광센서의 제작에 적합한 유리재료들의 종류와 특성을 설명하였으며, 이들 유리의 종류에 맞도록 개발되어진 제작기술 중에서 이온교환(Ion exchange)방법과 silica-on-silicon(SOS)방법을 소개하였다. 그리고 이러한 공정기술을 이용하여 제작되어진 유리 집적광센서 중에서 물체의 거리를 측정하기 위한 마이클슨 간섭계(michelson interferometer)와 물질의 농도를 측정하기 위한 화학센서(chemical sensor)들을 소개하였다.

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