• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.23-29
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• 2022

To detect harmful chemical substances in seawater, we fabricated a prototype sensor and evaluated its performance. The prototype sensor consisted of a detector, housing, and driving circuit. We built the detector by printing an Indium-Tin-Oxide (ITO) nanoparticle film on a flexible substrate, and it had two detection parts for simultaneous detection of temperature and HNS concentration. The housing connected the detector and the driving circuit and was made of Teflon material to prevent chemical reactions that may affect sensor performance. The driving circuit supplied electric power, and display measured data using a bridge circuit and an Arduino board. We evaluated the sensor performances such as response (ΔR), the limit of detection (LOD), response time, and errors to confirm the specification.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.1978-1982
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• 2006

The EPIRB overcame the limitations of the conventional marine communication systems, the false distress calls by EPIRB systems internationally account for about 94 percent of the total calls because of the different usages of EPIRB systems with manufacturers, users' errors, and systems' faults. To resolve these problems, international bodies and manufacturers are developing many measures to reduce those error emissions. In conventional systems, the distress call was sent immediately after the EPIRB is removed from the automatic release system. Taking into account the properties of the system, however manufacturers improved the operation so that the distress call is sent only when the EPIRB is released and then immersed into water. In spite of these efforts, the error emissions have not significantly reduced. In this study, the domestic and international technical regulations and standards for the COSPAS-SARSAT and satellite EPIRB systems were reviewed, and a bridge-type water detection sensor was developed to minimize the error emission from EPIRB.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.325-329
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• 2016

In this study, we investigated the feasibility of using printed Indium Tin Oxide (ITO) film as a remote sensor for Hazardous and Noxious Substances (HNS). To improve the quality of the ITO films, binder mixing ratio, Sn concentration in ITO, thermal treatment temperature, and printing process conditions were optimized. We fabricated an electrical resistance-type liquid sensor, and to confirm the sensor operation, the change in resistance in air and seawater was monitored. The change in resistance of the ITO sensor was explained in terms of reduction reaction on the surface. Further, the sensor was controlled by Arduino, and the remote data acquisition was demonstrated.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.23-29
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• 2017

The packaged optical fiber Bragg grating sensors which were networked by multiplexing the Bragg grating sensors with WDM technology were investigated in application for the structural health monitoring of the marine trestle structure transporting the ship. The optical fiber Bragg grating sensor was packaged in a cylindrical shape made of aluminum tubes. Furthermore, after the packaged optical fiber sensor was inserted in polymeric tube, the epoxy was filled inside the tube so that the sensor has resistance and durability against sea water. The packaged optical fiber sensor component was investigated under 0.2 MPa of hydraulic pressure and was found to be robust. The number and location of Bragg gratings attached at the trestle were determined where the trestle was subject to high displacement obtained by the finite element simulation. Strain of the part in the trestle being subjected to the maximum load was analyzed to be ${\sim}1000{\mu}{\varepsilon}$ and thus shift in Bragg wavelength of the sensor caused by the maximum load of the trestle was found to be ~1,200 pm. According to results of the finite element analysis, the Bragg wavelength spacings of the sensors were determined to have 3~5 nm without overlapping of grating wavelengths between sensors when the trestle was under loads and thus 50 of the grating sensors with each module consisting of 5 sensors could be networked within 150 nm optical window at 1550 nm wavelength of the Bragg wavelength interrogator. Shifts in Bragg wavelength of the 5 packaged optical fiber sensors attached at the mock trestle unit were well interrogated by the grating interrogator which used the optical fiber loop mirror, and the maximum strain rate was measured to be about $235.650{\mu}{\varepsilon}$. The modelling result of the sensor packaging and networking was in good agreements with experimental result each other.

• Journal of Advanced Navigation Technology
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• v.23 no.1
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• pp.61-68
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• 2019

Underwater wireless light communication system is quite necessary to retrieve recorded data from underwater devices or the black box without taking back it body. In this paper, a research on the light sensor technology in underwater wireless light communication under turbid sea was studied. A noise source under turbid sea for light communication was analysed, and a sensor system for light sensing using the reference light signal to remove the noises and to improve the output swing power wasstudied. Also, an underwater communication system was manufactured to validate the good performance of the development system, and using the system, the good performance of the developed system was validated through the light communication test in the tank containing the turbid sea water was presented.