• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.733-740
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• 2014

A resistive micro Pirani gauge using amorphous silicon (a-Si) thin membrane is proposed. The proposed Pirani gauge can be easily integrated with the other process-compatible membrane-type sensors, and can be applicable for in-situ vacuum monitoring inside the vacuum package without an additional process. The vacuum level is measured by the resistance changes of the membrane using the low noise correlated double sampling (CDS) capacitive trans-impedance amplifier (CTIA). The measured vacuum range of the Pirani gauge is 0.1 to 10 Torr. The sensitivity and non-linearity are measured to be 78 mV / Torr and 0.5% in the pressure range of 0.1 to 10 Torr. The output noise level is measured to be $268{\mu}V_{rms}$ in 0.5 Hz to 50 Hz, which is 41.2% smaller than conventional CTIA.

• Journal of Sensor Science and Technology
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• v.23 no.5
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• pp.326-331
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• 2014

In this study, a MEMS microphone that uses $Si_3N_4$ as the vibration membrane was produced for application as an auditory device using a sound visualization technique (sound visualization) for the hearing impaired. Two sheets of 6-inch silicon wafer were each fabricated into a vibration membrane and back plate, after which, wafer bonding was performed. A certain amount of charge was created between the bonded vibration membrane and the back plate electrodes, and a MEMS microphone that functioned through the capacitive method that uses change in such charge was fabricated. In order to evaluate the characteristics of the prepared MEMS microphone, the frequency flatness, frequency response, properties of phase between samples, and directivity according to the direction of sound source were analyzed. The MEMS microphone showed excellent flatness per frequency in the audio frequency (100 Hz-10 kHz) and a high response of at least -42 dB (sound pressure level). Further, a stable differential phase between the samples of within -3 dB was observed between 100 Hz-6 kHz. In particular, excellent omnidirectional properties were demonstrated in the frequency range of 125 Hz-4 kHz.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.73-78
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• 2015

Touch panel is mainly applied to pressure type touch panel but it occur a low recognition rate and error during long-term use. So, it is partly applied to capacitive touch panel to compensate for these problems but it also can occur a same problems via pollutions. Touch technology has developed a various method but it is not used because of high costs and difficult installation process. So, in this paper, we proposed an input method of touchless panel using IrDA matrix. This method is conducted using an IrDA Matrix composed of depth sensor. It is possible to offer a various contents for multi user. The proposed technology need a development of a high sensitivity sensing method and high-speed processing method of position information for Seamless operation control. And, it is required high-precision drive technology. Also, we proposed a Seamless user recognition for interactive contents service through a touchless panel using IrDA matrix.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.13-20
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• 2005

The most typical fuel control devices of motorcycle engines have carburetors, they are simple in structure and reliable in work. Most of the motorcycle engines have used carburetors in the fuel system, but the fuel economy and the emissions of those engines are bad when we compared with automobile engines. According to stricter emission regulations and higher requirements for fuel economy, the application of the carburetor on the motorcycle engines would be limited. In this paper, we studied about the ECU of motorcycle engine controled by indirect method. A new engine system was designed and experiments were carried out. The experimental results for both carburetor type and ECU type were compared. Maximum torque of $1.053kg{\cdot}m$ at 6500rpm was measured. The engine torque controled using ECU was increased by $10\%$ compared with the carburetor type.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.2
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• pp.1-8
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• 2012

This paper presents the accelerometer which is a key component of TPMS(Tire Pressure Monitoring System). Generally a piezoresistive accelerometer has characteristics of lower cost, better linearity and better immunity about the environmnet noise than a capacitive one. Three types of piezoresistive accelerometers are degined and simulated using ANSYS program. The best one is a piezoresistive sensor which is supported by four beams located at the center of the edge of the mass after comparing the characteristics of resonant frequency of the three types. Considering the sensor size and a simulated maximum stress and maximum displacement, the length of beams is set as $200{\mu}m$. The size of a piezoresistive accelerometer is $3.0mm{\times}3.0mm{\times}0.4mm$. The sensor output is characterized by measuring the output characteristic depending on angle. As a result the offset voltage of the accelerometer is 43.2 mV and its sensitivity is $42.5{\mu}V/V/g$. The temperature bias drift is measured. The shock durability of the sensor is 1500g and the measuring range is 0 ~ 60 g.