• Journal of Sensor Science and Technology
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• v.14 no.5
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• pp.302-307
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• 2005

Precision displacement of less than a few nm resolution was measured in real-time using fiber optic EFPI sensor. The novel method for real-time processing of analyzing EFPI output signal was developed and verified. Linearity in the mean values of interferometric light intensity among adjacent fringes was shown and verified the sinusoidal approximation algorithm that estimates past and coming fringe values. Real-time signal processing program was developed and the intensity signal of the EFPI sensor was transformed to the phase shift with this program. The resolution below $0.36{\sim}8.6$ nm in the displacement range of $0{\sim}300{\mu}m$ was obtained. The nano-positioner with a piezoelectric actuator and the EFPI sensor system was designed and tested. The positioner successfully reached to the desired destination within 1 nm accuracy.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.154-157
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• 2003

Precision displacement of less than a few nm resolution was measured in real-time using fiber optic EFPI sensor. The novel method for real-time processing of analyzing EFPI output signal was developed and verified. Linearity in the mean values of interferometric light intensity among adjacent fringes was shown, and the sinusoidal approximation algorithm that estimates past and coming fringe values was verified through the linearity. Real-time signal processing program was developed, and the intensity signal of the EFPI sensor was transformed to the phase shift with this program. The resolution below 0.4 ~ 10 nm in the displacement range of $0 ~ 300\mu\textrm{m}$ was obtained by reducing the photodetector noise using low-pass filter and signal averaging. The nano-translation stage with a Piezo-electric actuator and the EFPI sensor system was designed and tested. This stage successfully reached to the desired destination in $15\mu\textrm{m}$ range within 1 nm accuracy.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.3
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• pp.247-252
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• 2014

This paper presents a novel impact sensor which can be fabricated with smart paint made of grapheme. This smart nano paint can be easily installed on structures using a spray-on technique and that can make the sensor low cost and practical. The graphene effectively improves the piezoresistivity of the smart paint and that is available to achieve sensitive impact sensor with high gauge factor. The nano smart-paint can detect sufficient impact to cover the damaged energy range of the composite around 1~3J. The voltage outputs from the sprayed paints show fairly linear responses after signal processing. The impact makes deformation of the structure and it brings change of piezoresistivity of the paint and those converts into voltage output consequently by means of a simple signal processing system. The nano smart paint is lightweight and easily applied to the structural surface, and there is no stress concentration. The nano smart paint is expected to be a cost effective and sensitive multi-functional sensor for composites and other damage monitoring applications in the field of structural health monitoring.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.2
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• pp.149-156
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• 2014

Flexible tactile sensors can provide valuable feedback to intelligent robots about the environment. This is especially important when the robots, e.g., service robots, are sharing the workspace with human. This paper presents a flexible tactile sensor that was manufactured by direct writing technique, which is one of 3D printing method with multi-walled carbon nano-tubes. The signal processing system consists of two parts: analog circuits to amplify and filter the sensor output and digital signal processing algorithms to reduce undesired noise. Finally, experimental setup is implemented and evaluated to identify the characteristics of the flexible tactile sensor system. This paper showed that this type of sensors can detect the initiation and termination of contacts with appropriate signal processing.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.877-884
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• 2016

Nano communication system technologies are future core technologies that facilitate the implementation of tiny wireless communication systems with sizes in the range of hundreds of nanometers to tens of micrometers, which cannot be implemented by current wireless communication system technologies. In particular, novel nano communication system technology, which is based on electrical and mechanical resonance characteristics of carbon nanotube(: CNT), does not simply miniaturize system modules, but suggests a new approach that changes system architectures. Therefore, this paper surveys the state of the art on CNT-based nano communication technologies in aspects of system implementation, and proposes important research issues for convergence of nano and communication technologies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.1030-1037
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• 2009

SAW Sensor is greatly developed today and Reader Platform which uses SAW Sensor for temperature or pressure is required to use TDS method for low power and high speed processing. For to use this Platform, high speed timer is required to measure a short interval between reference signal and reflectior's signal. This paper proposes that platform receive SAW Sensor's signals and transform digital signal through comparator. Next the transformed signal is measured by Timer Platform and the measured interval is displayed with time. This paper proposes method of measurment of time with nano sec unit.

• ETRI Journal
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• v.32 no.2
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• pp.319-326
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• 2010

Photonics offers a solution to data communication between logic devices in computing systems; however, the integration of photonic components into electronic chips is rather limited due to their size incompatibility. Dimensions of photonic components are therefore being forced to be scaled down dramatically to achieve a much higher system performance. To integrate these nano-photonic components, surface plasmon-polaritons and/or energy transfer mechanisms are used to form plasmonic chips. In this paper, the operating principle of plasmonic waveguide devices is reviewed within the mid-infrared spectral region at the 2 ${\mu}m$ to 5 ${\mu}m$ range, including lossless signal propagation by introducing gain. Experimental results demonstrate that these plasmonic devices, of sizes approximately half of the operating free-space wavelengths, require less gain to achieve lossless propagation. Through optimization of device performance by means of methods such as the use of new plasmonic waveguide materials that exhibit a much lower minimal loss value, these plasmonic devices can significantly impact electronic systems used in data communications, signal processing, and sensors industries.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.12 s.354
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• pp.9-15
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• 2006

In this paper, signal processing techniques for noncoherent impulse-radio-based UWB (IR-UWB) communication system are proposed to provide system implementation of low power consumption and low complexity. The proposed system adopts a simple modulation technique of OOK (on-oft-keying) and noncoherent signal detection based on signal amplitude. In particular, a technique of a novel high speed digital sampler using a stable, lower reference clock is developed to detect nano-second pulses and recover digital signals from the pulses. Also, a 32 bits Turyn code for data frame synchronization and a convolution code as FEC are applied, respectively. To verify the proposed signal processing techniques for low power, low complexity noncoherent IR-UWB system, the proposed signal processing technique is implemented in FPGA and then a short-range communication system for wireless transmission of high quality MP3 data is designed and tested.

• Journal of Drive and Control
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• v.13 no.1
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• pp.43-48
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• 2016

This paper presents a preliminary study on the pressure sensing characteristics of smart nano composites made of MWCNT (multi-walled carbon nanotube) to develop a novel pressure sensor. We fabricated the composite pressure sensor by using a solution casting process. Made of carbon smart nano composites, the sensor works by means of piezoresistivity under pressure. We built a signal processing system similar to a conventional strain gage system. The sensor voltage outputs during the experiment for the pressure sensor and the resistance changes of the MWCNT as well as the epoxy based on the smart nano composite under static pressure were fairly stable and showed quite consistent responses under lab level tests. We confirmed that the response time characteristics of MWCNT nano composites with epoxy were faster than the MWCNT/EPDM sensor under static loads.

• The Journal of the Acoustical Society of Korea
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• v.13 no.6
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• pp.24-30
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• 1994

In this paper, the system for detection of photoacoustic signal has been constructed by using CW $CO_{2}$ laser for an analysis of the photoacoustic signal In metals and aluminum carbon steel, brass have been used as sample. The photoacoustic signals of several nano amperes have been detected in each sample with varying modulation frequency of laser, time constant of lock-in amplifier, thickness of sample. The characteristics of photoacoustic signal has been analysed in term of phase angle by using signal processing technique. Results indicate that the photoacoustic signal can be stabilized by adjustment of time constant of lock-in amplifier, that the signal amplitude is proportional to the ratio of thermal expansion coefficient to thermal capacity of metal, and that the signal amplitude decreases exponentially with sample thickness as well as with modulation frequency.