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Byeongju Lee;Jin-Oh Lee;Junyeong Lee;Inkyu Park;Dae-Sik Lee
- Journal of Sensor Science and Technology
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- v.32 no.1
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- pp.1-9
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- 2023
Recently, the digital healthcare technologies including non-invasive diagnostics based on Internet of Things (IOT) are getting attention. Human exhaled breath contains a variety of volatile organic compounds (VOCs), which can provide information of malfunctions of the body and presence of a specific disease. Detection of VOCs in exhaled breath using gas sensors are easy to use, safe, and cost-effective. However, accurate diagnosis of diseases is challenging because changes in concentration of VOCs are extremely small and lots of body factors directly or indirectly influence to the conditions. To overcome the limitations, highly selective nanosensors and artificial intelligent electronic nose (E-nose) systems have been mainly researched in recent decades. This review provides brief reviews of the recent studies for diabetes and lung cancer diagnosis using nanosensors and E-nose systems.
https://doi.org/10.46670/JSST.2023.32.1.1 인용 PDF

Lee, Min-Rae;Lee, Jun-Hyeon
- Transactions of the Korean Society of Mechanical Engineers A
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- v.26 no.5
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- pp.864-871
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- 2002
Acoustic emission(AE) technique has been applied to not only mechanical property testing but also on-line monitoring of the entire structure or a limit zone only. Although several AE devices have already been developed for on-line monitoring, the price of these systems is very high and it is difficult for the field to apply yet. In this study, we developed a specially designed PC-based leak detection system using A/D board. In this paper, AE technique has been applied to detect leak for heat exchanger by analyzing the characteristics of signal obtained from leak. It was confirmed that the characteristics of the signal generated by the turbulence of gas in the heat exchanger is narrow band signal having between 130-250kHz. Generally, the amplitude of leak signal is increased as the leak size increasing, but showed no significant change at frequency characteristic. Leak source location can be found by determining for the paint of highest signal amplitude by comparing with several fixed sensors. In this paper, AE results are compared with the PC-based leak detection system using A/D board.
https://doi.org/10.3795/KSME-A.2002.26.5.864 인용 PDF KSCI

Park, Gyou-Tae;Lyu, Keun-Jun;Han, Sang-In;Oh, Jeong-Seok;Kim, Ji-Yoon;Ahn, Sang-Guk;Yoon, Myung-Seop;Kwon, Jeong-Rock
- Journal of the Korean Institute of Gas
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- v.12 no.2
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- pp.48-52
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- 2008
According to extremely industrial growth, gas facilities, equipments and chemical plants are gradually increased due to incremental demands of annual amount of gases. The safety management of gases, however, is still far from their requirements. Methane, the principal ingredient of natural gas, is inflammable and explosive and is much used in factories and houses. Therefore, these gas safety management is essential. So, we, with a program of the gas safety management, hope to develop the detection system of methane gas leak using mid-infrared ray LED and PD with $3.2\;{\mu}m$. The cryogenic cooling device is indispensible at laser but needless at LED driven on the room temperature if manufacturing optical sensor with $3.2\;{\mu}m$. It, consequently, is not only possible to implement for subminiature and portable type but also able to speedily detect methane of extremely small quantities because the $CH_4$ absorption intensity at $3.2\;{\mu}m$ is stronger than that at $1.67\;{\mu}m$. Our objective of research is to prevent gas leak accidents from occurring previously and to minimize the extent of damage from them.
PDF

김의락
- KSBB Journal
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- v.18 no.2
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- pp.79-89
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- 2003
This article contains an overview of acoustic wave devices, the theory and application of piezoelectric quartz crystal microbalances(PZ QCM), clinical analysis, gas phase detection, DNA biosensors, drug analysis, food microbial analysis and environmental analysis.
PDF KSCI