• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.261-263
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• 1996

The study on the development of one-channel gas sensor using the quartz crystal analyzer were attempted. The adsorption and desorption behavior of organic gases were investigated using the resonant frequency and resistance method of quartz crystal. The sensitive materials were deposited on the quartz crystal analyzer(QCA) by using Langmuir-Blodgett method. To investigate the response characteristics of organic vapours and response mechanism, resonant frequency-resonant resistance (F-R) diagram was used. In our experimental results, the response mechanism between sensitive LB film and organic vapours was obtained using F-R diagram. And the position of each organic vapour were different as to the kind and injection amount. Thus F-R diagram can be applied to one-channel gas sensor using the QCA and useful to analyze the response mechanism between organic vspours and sensitive LB films.

• Journal of Sensor Science and Technology
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• v.24 no.3
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• pp.181-187
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• 2015

The magnetoelectric characteristics on layered $Fe_{78}B_{13}Si_9/PZT$ and $Fe_{78}B_{13}Si_9/PZT/Fe_{78}B_{13}Si_9$($t_m=0.017$, 0.034mm) composites by epoxy bonding for magnetic field sensor were investigated in the low-frequency range and resonance frequency range. The optimal bias magnetic field $H_{dc}$ of these samples was about 23~63 Oe range. The Me coefficient of $Fe_{78}B_{13}Si_9/PZT/Fe_{78}B_{13}Si_9(t_m=0.034mm)$ composites reaches a maximum of $186mV/cm{\cdot}Oe$ at $H_{dc}=63Oe$, f=50 Hz and a maximum of $1280mV/cm{\cdot}Oe$ at $H_{dc}=63Oe$, resonance frequency $f_r=95.5KHz$. The output voltage shows linearity proportional to ac fields $H_{ac}$ and is about U=0~130.6 mV at $H_{ac}=0{\sim}7Oe$, f=50 Hz, U=0~12.4 V at $H_{ac}=0{\sim}10Oe$, $f_r=95.5KHz$(resonance frequency). The optimal frequency(f=50 Hz) of this sample is around the utility ac frequency(f=60 Hz). Therefore, this sample will allow for ac magnetic field sensor at utility frequency and low bias magnetic fields $H_{dc}$.

• Journal of Sensor Science and Technology
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• v.19 no.5
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• pp.391-397
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• 2010

This paper proposes a differential structure sensor for detecting Ringer's solution exhaustion, in which three C-type electrodes of 10 mm width are disposed on a ringer hose at a distance of 5 mm each other in the direction of Ringer's solution flow. In the center of middle electrode, two capacitances are formed at the proposed sensor. When ringer hose is filled with Ringer's solution, there is no difference between two capacitances. But capacitance difference exist under the Ringer's solution shortage, because the shortage causes the hose filled with air from the top position electrode. The capacitance difference got to maximum 1.81 pF, when air was filled between top and middle electrode and the last of hose was filled with 10 % dextrose injection Ringer's solution. The capacitance difference varied with hose-wraparound coverage of electrodes as well as the width of them. For hose-wraparound electrode coverage of 90 % and 70 %, the maximum capacitance difference was 1.81 pF and 1.56 pF, respectively. A differential charge amplifier converted the capacitance difference to electric signal, and minimized electrodes' adhering problem and external noise coupling problem.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.91-98
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• 2013

Magnetic sensor chip for measuring bio-magnetism is implemented in $0.18{\mu}m$ CMOS technology. The magnetic sensor chip consists of a small-sized high inductance coil sensor and an instrumentation amplifier (IA). High inductance coil sensor with suitable sensitivity and bandwidth for measurement of bio-magnetic signal is designed using electromagnetic field simulation. Low gm operational transconductance amplifier (OTA) using transconductance reduction techniques is designed for on-chip solution. Output signal sensitivity of magnetic sensor chip is $3.25fT/{\mu}V$ and reference noise of 21.1fT/${\surd}$Hz. Proposed IA is designed along with band pass filters(BPF) to reduce magnetic signal noise by using current feedback techniques. Proposed IA achieves a common mode rejection ratio of 117.5dB while the input noise referred is kept below $0.87{\mu}V$.

• The Journal of Korea Robotics Society
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• v.13 no.4
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• pp.230-236
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• 2018

3D depth perception has played an important role in robotics, and many sensory methods have also proposed for it. As a photodetector for 3D sensing, single photon avalanche diode (SPAD) is suggested due to sensitivity and accuracy. We have researched for applying a SPAD chip in our fusion system of time-of-fight (ToF) sensor and stereo camera. Our goal is to upsample of SPAD resolution using RGB stereo camera. Currently, we have 64 x 32 resolution SPAD ToF Sensor, even though there are higher resolution depth sensors such as Kinect V2 and Cube-Eye. This may be a weak point of our system, however we exploit this gap using a transition of idea. A convolution neural network (CNN) is designed to upsample our low resolution depth map using the data of the higher resolution depth as label data. Then, the upsampled depth data using CNN and stereo camera depth data are fused using semi-global matching (SGM) algorithm. We proposed simplified fusion method created for the embedded system.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.26-34
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• 1998

In this paper, a force control algorithm for edge following task is suggested. Through the contact state modeling between rigid part and end-effector of robot, contact force and contact angle that are essencial parameters to build the control strategies for following movement of end-effector are derived. From these two parameters, we discriminate the every contact state into 8 cases and calculate the new moving position and direction simply. For the experiment. RX90 robot from Staubli with robot language V$^{+}$ is applied and F/T sensor is attached to the wrist of robot with RCC. Finally, 3 edge following experiments including the following of corner point are executed with successful results.s.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.119-123
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• 2015

This paper presents the inkjet-printed flexible temperature and humidity sensor(F-TH sensor) using PEDOT:PSS. The series, mesh and parallel type sensing element using PEDOT:PSS ink was printed on the overhead projector(OHP) film. The fabricated sensor of each structure has the temperature sensitivity of $140{\Omega}/^{\circ}C$, $29{\Omega}/^{\circ}C$ and $1.4{\Omega}/^{\circ}C$ with linearity, respectively. Also the fabricated sensor was not only possible to measure a temperature, but also to detect humidity. The humidity sensitivity of $400{\Omega}/%RH$, $3.4{\Omega}/%RH$ and $3{\Omega}/%RH$ with linearity, respectively. The fabricated F-TH sensor is expected for the various applications such as electronic devices, bio-healthcare, industrial field.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.1
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• pp.109-114
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• 2024

The bio-sensing properties of TE and TM guided modes in the coupled plasmon-waveguide resonance (PWR) configuration are investigated. The modal transmission-line theory (MTLT) is used for numerical analysis. The proposed PWR bio-sensor is composed of multi-layered configuration with N pairs of MgF2-Si3N4 layers to enhance the sensitivity of a conventional Ag-based surface plasmon resonance bio-sensor. The angular sensitivity of bio-sensor is numerically analyzed for a wide range of biological solutions (refractive index 1.33~1.37). Furthermore, the availability of sensor to detect cancer cells and blood plasma concentration is evaluated. Finally, the results indicate that the proposed bio-sensor is capable efficiently to detect various kinds of cancer cells and different glucose concentrations in urine.

• Journal of Sensor Science and Technology
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• v.24 no.3
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• pp.208-213
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• 2015

The purpose of this study is to optimize the design of a capacitive pressure sensor element using the simulation of electrical characteristics. The simulation of the ceramic sensor diaphragm ($Al_2O_3$) was performed by permitting pressure to change the curvature of the diaphragm. The pressure capacitance ($C_P$) was increased from 19.63 pF to 15.26 pF by applying pressure because the distance between the electrodes has been changed from $30{\mu}m$ to $15{\mu}m$. When the thickness of the diaphragm was changed to 0.46~0.52 mm, a larger capacitance change showed in accordance with the reduced thickness, which means an increase of sensitivity. However, considering the viewpoint of the signal linearity, it was selected for the optimum thickness of the diaphragm to 0.50 mm. The designed sensor element based on simulated results was tested to measure the output characteristics. Comparing of simulated and measured results, there was a margin of error of approximately 2%.

• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.409-414
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• 2004

A signal processing system of long period grating sensor that works in the optical wavelength domain is proposed. The system is based on a wavelength-swept semiconductor light source that includes an SLD and a F-P tunable filter. The hysteresis effects of PZT in the F-P filter is compensated by using an etalon filter and an athermal Fiber Bragg Grating. The detected signals from the photodiode are transmitted to a computer using an A/D converter and the result of the process is displayed in the monitor.