• Proceedings of the KOSOMBE Conference
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• v.1991 no.05
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• pp.98-100
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• 1991

A sensitive surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing different phospholipids and fatty acids on the surface of the SAW device wi th the Langmuir-Blodgett technique. The characteristics of SAW device operating at 310 MHz deposited with phosphatidylcholine were analyzed. Amyl acetate, acetoin, menthone and other organic gases showed different affinities. The identification of odorants depending on the species of lipid used for coating is discussed in terms of the similarity of the normalized resonant frequency shift pattern. Using a number of different lipid-coated SAW devices, odorants could be identified by a neural-network pattern recognition with back-propagation algorithm.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.223-226
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• 2003

This paper presents a realization of sensor signal processing(noise filtering) and Fieldbus based communication for condition monitoring of check valve. we first acquired the AE(Acoustic Emission) sensor data at the KAERI check valve test loop, and their frequencies were analyzed to find the informative band. To reject background noises, bandpass filters have been designed. Also, to send the processed data to a remote site, wired communication facility has been realized via DeviceNet.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.437-440
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• 2007

This paper presents the improvement of the resonance characteristics of film bulk acoustic-wave resonator (FBAR) devices fabricated on multilayer Bragg reflectors (BRs) based on inserting ultra-thin chromium (Cr) adhesion layers into BRs and post-annealing processes. The measurements show excellent improvement of return loss $(S_{11})$ and Q-factor by the combined use of Cr adhesion layers and thermal treatments particularly for 120 minutes at $200^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.703-706
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• 2002

Piezoelectric thin film such as ZnO and AlN can be applicable to FBAR (Film Bulk Acoustic Resonator) device of thin film type and FBAR can be applicable to MMIC. The characteristic of FBAR device is variable according to the deposition conditions of piezoelectric thin film when preparation of thin film by sputtering method. In this study, we prepared ZnO thin film for FBAR using Facing Targets Sputtering apparatus which can be deposited fine Quality thin film because temperature increase of substrate due to the bombardment of high-energy particles can be restrained. And crystalline and c-axis preferred orientation of ZnO thin film with deposition conditions was investigated by XRD.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.9 s.240
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• pp.1276-1281
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• 2005

Compound semiconductors are the semiconductors composed of more than two chemical elements. Lithium Tantalate$K_I$ wafer is used for several optical devices, especially surface acoustic wave(SAW) device. Because of the lithography in SAW device process, $LiTaO_3$ polishing is needed. In this paper, the commercial slurries $(NALC02371^{TM},\; ILD1300^{TM},\;ceria slurry)$ used for chemical mechanical polishing(CMP) were tested, and the most suitable slurry was selected by measuring material removal rate and average centerline roughness$(R_a)$. From these result, it was proven that $ILD1300^{TM}$ was the most suitable slurry for $LiTaO_3$ wafer CMP due to the chemical reaction between solution in slurry and material.

• Transactions of the Society of Information Storage Systems
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• v.8 no.1
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• pp.16-21
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• 2012

SAW device is widely used as filters, sensors, actuators in various technologies. And capacitive sensor is tremendously used to measure pressure, gap, etc. The application of SAW device as signal conditioner of capacitive sensor reduces noise level and enables high precision measurement. The response increase of SAW based capacitive sensor is produced just before the two capacitive electrode contacts by the existence of parasitic resistance of capacitive electrode. In this paper, we analyze the effects of parasitic resistance and propose the calibrating method using lumped component and execute the high precision gap measurement using calibrated system. And xx nm resolution and yy ${\mu}m$ stroke was attained.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1457-1459
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• 1994

A surface acoustic wave(SAW) sensor for the detection of odorants has been constructed by depositing various phospholipids and fatty acids onto the surface of the SAW device. Applying the Langmuir-Blodgett technique, it was possible to deposit the optimal number of layers which was found to be between 10 and 20. Menthone, amylacetate, acetoin, and other organic gases showed different affinities to the coated lipids. An explanation is given for different odorant affinities based on the monolayer properties of phospholipids.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.975-976
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• 2006

The passive type RFID (Radio Frequency Identification) System using Surface Acoustic Wave (SAW) tag at 900 MHz in the range of more than 1 m was fabricated. To improve interrogation range of the system propose a method to increase isolation between transmitter and receiver. This method using a direct conversion architecture achieves a leakage rejection of 10 dB increased compared with conventional system. Measured interrogation range is more than 1 m.

• International Journal of Computer Science & Network Security
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• v.21 no.4
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• pp.277-283
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• 2021

The objective of this project is to conduct an underwater survey. The primary goal is to develop a device that can achieve the desired output under test conditions. For this reason, certain practical considerations must be taken into account, and the implementation is then developed to be carried out to obtain stable performance with the available hardware based on that experiment. The experiment was performed via BlueROV2 (Remotely Operated Vehicle) using RaspberryPi and softwares such as QGC (QGroundControl) and ArduPilot. This paper explains the work, the results with the collected data and how we implemented the work is presented in the end. The intention of this experiment is to connect two PCs using RaspberryPi with MAVLink communication using a Commercial-Off-The-Shelf device.

• Journal of Science Education
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• v.37 no.1
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• pp.233-243
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• 2013

The purpose of this study is to develop the syringe experiment device which is able to analyze the relationship between the length of the air pillar and resonance frequencies quantitatively for the education of sound resonance. We made an air pillar resonance device with a 'Head', which is used by the disposable syringe and the plastic sphere for constructing molecular models. We also assembled PC experiment equipment which is used by commercial software. As a result, it appears this equipment can be used instead of the current device used by experts. It was proved that this syringe device is not the 'pipe' but the 'Helmholtz resonator'. It appears that data through resonance experiments can prove the sound resonance phenomenon. In conclusion, this syringe resonator is the experiment device that can be used in the gifted education for middle-high school students and acoustic experiments for university students.