• Journal of Magnetics
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• v.14 no.3
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• pp.132-136
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• 2009

This study investigated the radial pulse waveform obtained by a medical pulsimeter sensor. A pulse-sensing part array consisting of multiple Hall devices was located over a skin-contacting part with a hard magnetic material. The periodic movement of the magnetic material of the skin-contacting part affected the magnetic field in the pulse-sensing part array and was detected by multiple Hall devices. The analysis of a radial pulse waveform that is measured noninvasively by detecting the changes of the magnetic field can be used to develop a new diagnostic algorithm of oriental medical apparatus.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.132-132
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• 2003

• Proceedings of the Korean Ceranic Society Conference
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• 2000.04a
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• pp.37.1-37.1
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• 2000

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.156-156
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• 1997

• Journal of the Korean institute of surface engineering
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• v.49 no.1
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• pp.75-80
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• 2016

$In_2O_3$ nanowires were coated with $Co_3O_4$ nanoparticles to investigate the improvement of ethanol gas sensing performance compared with as-synthesized $In_2O_3$ nanowires. Scanning electron microscopy showed that the nanowires synthesized by VLS mechanism had diameters and lengths of approximately 50-100 nm and a few micrometers, respectively. $Co_3O_4$ nanoparticles produced by hydrothermal method was in the size range of a few to a few tens nm. As-synthesized and $Co_3O_4$ nanoparticles coated $In_2O_3$ nanowires sensors exhibited responses of 1.96% and 4.57%, respectively for the ethanol gas concentration of 200 ppm at $200^{\circ}C$. The underlying mechanism for the improved responses of $Co_3O_4$ nanoparticles coated $In_2O_3$ nanowires sensors is discussed.

• Journal of the Korean Magnetics Society
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• v.10 no.4
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• pp.159-163
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• 2000

MR characteristics in magnetic tunnel junction using CoO as the oxide barrier were investigated. Spin-dependent tunnel junctions were fabricated on 4$\^$o/ tilt-cut (111)Si substrates in 3-gun magnetron sputtering system. The top and bottom ferromagnetic electrodes were Ni$\_$80/Fe$\_$20/(300 $\AA$) and Co(300 $\AA$), respectively. The oxide barriers (CoO) were formed by the thermal oxidation at room temperature in an O$_2$ atmosphere and the plasma oxidation. The increase of coercive field due to antiferromagnetic-ferromagnetic coupling has been observed in O$_2$plasma-oxidized CoO based junctions at room temperature. At a sensing current of 1 mA, MR ratios of O$_2$plasma-oxidized CoO based junction and thermal-oxidized CoO based junction at room temperature were 1% and 5%, respectively. Larger MR ratios are observed in magnetic tunnel juctions with thermal oxidized CoO when sensing current more than applied 1.5 mA. At a sensing current of 1.5 mA, we have observed MR value of 28 % and specific resistance (RA=R$\times$A) value of 10.9 ㏀$\times$㎛$^2$. When specific resistance values reached 2.28 ㏀$\times$㎛$^2$, we have observed that MR ratios become as high as 120%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.460-463
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• 2002

$MoO_3$ thin films were deposited on electrode and heater screen-printed alumina substrates in $O_2$ atmosphere by RF reactive sputtering using Molybdenum metal target. The deposition was performed at $300^{\circ}C$ with 350W of a forward power in an $Ar-O_2$ atmosphere. The working pressure was maintained at $3{\times}10^{-2}mtorr$ and all deposited films were annealed at $500^{\circ}C$ for 5hours. To investigate gas sensing characteristics of the addition doped $MoO_3$ thin film, Co, Ni and Pt were used as adding dopants. The sensing properties were investigated in tenn of gas concentration under exposure of reducing gases such as $H_2$, $NH_3$ and CO at optimum working temperature. Co-doped $MoO_3$ thin film shows the maximum 46.8% of sensitivity in $NH_3$ and Ni-doped $MoO_3$ thin film exhibits 49.7% of sensitivity in $H_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.8
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• pp.705-710
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• 2003

MoO$_3$thin films were deposited on electrode of alumina substrates in $O_2$atmosphere by RF reactive sputtering using molybdenum metal target. The deposition was performed at 30$0^{\circ}C$ with 350 W of a forward power in an Ar-O$_2$atmosphere. The working pressure was maintained at 3$\times$10$^{-2}$ torr and all deposited films were annealed at 50$0^{\circ}C$ for 5 hours. The surface morphology of films was observed by using a SEM and crystalline phases were analyzed by using a XRD. To investigate gas sensing characteristics of the doped MoO$_3$thin film, Co, Ni and Pt were used as dopants. The sensing properties were investigated in term of gas concentration under exposure of reducing gases such as H$_2$, NH$_3$and CO at optimum working temperature. Co-doped MoO3 thin film shows the maximum 46.8 % of sensitivity in NH$_3$ and Ni-doped MoO$_3$thin film exhibits 49.7 % of sensitivity in H$_2$.

• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.64-69
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• 2017

The rapid growth of algae occurs can induce the algae bloom when nutrients are supplied from anthropogenic sources such as fertilizer, animal waste or sewage in runoff the water currents or upwelling naturally. The algae blooms creates the human health problem in the environment as well as in the water resource managers including hypoxic dead zones and harmful toxins and pose challenges to water treatment systems. The algal blooms in the source water in water treatment systems affects the drinking water taste & odor while clogging or damaging filtration systems and putting a strain on the systems designed to remove algal toxins from the source water. This paper propose the emerging In-Situ self-diagnosable smart algae sensing device with wireless connectivity for smart remote monitoring and control. In this research, we developed the In-Site Algae diagnosable sensing device with wireless sensor network (WSN) connectivity with Optical Biological Sensor and environmental sensor to monitor the water treatment systems. The proposed system emulated in real-time on the water treatment plant and functional evaluation parameters are presented as part of the conceptual proof to the proposed research.

• Korean Journal of Remote Sensing
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• v.18 no.3
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• pp.147-153
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• 2002

The real-time reception and recording of down-link mission data from a satellite requires the highest reliability because the data lost in receiving process cannot be recovered. The data receiving and recording system has moved from a set of dedicated hardware and software components to commercial-off-the-shelf (COTS) components in order to reduce the system cost as well as to upgrade the system easily for handling other satellite data. The use of COTS hardware and middleware components prevents the system developer from correcting or modifying the internal operations of the COTS components, and hence, instant performance degradation of the COTS components which affects the reliable data acquisition must be covered by a software algorithm. This paper introduces the instant performance problem of a COTS data recording device which leads to the data loss in the real-time data reception and recording process. As a result, the requirement of the modification of the conventional data read/write technique is issued. In order to overcome the data loss problem due to the use of COTS components and the conventional software technique, a new algorithm called a software buffering technique is proposed. The experiments show that the application of the proposed technique results in reliable real-time reception and recording of high speed serial data.