• Journal of Sensor Science and Technology
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• v.12 no.2
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• pp.79-87
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• 2003

In this paper, we propose a method to obtain a linear characteristic using soft computing for systems which have array sensors of nonlinear characteristics. Also a procedure utilizing the pattern information of array sensors without additional sensors is proposed to reduce disturbance effects. For a typical example, even a single CdS cell for CdS array has nonlinear characteristics. Overall linear characteristic for CdS array is obtained using fuzzy logic for each cell and overlapped portion. In addition, further improvement for linearization is obtained applying genetic algorithms for the parameters of membership functions. Also the effect of disturbing external light changes to the CdS array can be reduced without using any additional sensors for calibration. The proposed method based on fuzzy logic shows improvements for position measurements and disturbance reduction to external light changes due to the fuzziness of the shadow boundary as well as the inherent nonlinearity of the CdS array. This improvement is shown by applying the proposed method to the ball position measurements of a magnetic levitation system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2045-2048
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• 2006

This study presented the non-contact human interface using by CdS sensor array. We are pointing the light on the target to measure the value. We converted the CdS sensors value to digital value and applied the digital value to set the coordinate value from the ratio of it to the adjacent sensors. The indicated coordinate-value is presented on the PC screen by LabVIEW The experimental result, we could confirm the right value divided between each sensor distance into In parts.

• Journal of Sensor Science and Technology
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• v.5 no.3
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• pp.41-48
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• 1996

We developed SAW gas sensor for monitoring SOx gas with high sensitivity. It was fabricated as a microsensor for detecting SOx gas by depositing sensing material on SAW device. As a detecting layer material, CdS was selected. Deposition of CdS in the form of thin films was carried out by the ultrasonic spray pyrolysis method using ultrasonic spray nozzle. Thin films with the uniform and large surface area for sensors were deposited. The stable pyrolysis environment provided by uniform and fine droplets formed by spray nozzle made it possible to obtain thin films with excellent quality. The minimum grain size of the CdS thin films was about 50 nm when deposited at $300^{\circ}C$. SAW gas sensors showed reasonable sensitivity and reproducibility. Further studies are required to investigate the interference of other gases to SOx gas detection.

• Journal of Sensor Science and Technology
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• v.6 no.5
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• pp.414-422
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• 1997

CdS thin films with low resistivity and adequate transmittance in the visible region for the window of CdS/CdTe hetero junction solar cel1 were prepared by close spaced vapor transport(CSVT) method. The electrical and optical properties of the CdS thin films were investigated in terms of the deposition conditions, such as the substrate temperature, the working pressure, and the source temperature. The substrate temperature, the working pressure, and the source temperature for the optimum deposition of the CdS thin films were $300^{\circ}C$, 100mTorr, and $730^{\circ}C$, respectively. The resistivity and the transmittance of the CdS thin films deposited under this condition were about $7.21{\times}10^{3}{\Omega}cm$ and over 65%, respectively. The crystallinity, the resistivity, and optical band gap were improved greatly compared to the CdS thin films deposited by general high vacuum evaporation.

• Journal of Sensor Science and Technology
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• v.6 no.2
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• pp.163-171
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• 1997

CdS thin films for window material of solar cell were prepared by close spaced vapor transport deposition system and annealed at different temperatures. The structural, electrical, and optical properties of as-deposited and annealed CdS films were investigated as functions of substrate and annealing temperatures. The CdS thin films were grown perpendicularly to the substrate along the (002)plane with hexagonal structure regardless of the preparation conditions The resistivity of the CdS film deposited was increased gradually from $60{\Omega}cm$ for $25^{\circ}C$ to $2{\times}10^{4}{\Omega}cm$ for $300^{\circ}C$. The optical transmittance at the substrate temperature of $25^{\circ}C$ was about 80% in the the visible spectrum. The resistivity increased monotonically, and the optical transmittance was decreased substantially with annealing temperature due to the increased defect density in the CdS film.

• Journal of Sensor Science and Technology
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• v.1 no.1
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• pp.53-57
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• 1992

We report the crystal growth and the electro-optic characteristics of $CdS_{1-x}Se_{x}$ thin films. $CdS_{1-x}Se_{x}$ thin films wire deposited on the alumina plate by electron beam evaporation technique in pressure of $1.5{\times}10^{-7}$ torr, voltage of 4kV, current of 2.5mA and substrate temperature of $300^{\circ}C$. The deposited $CdS_{1-x}Se_{x}$ thin films were proved to be a polycrystal with hexagonal structure through X-ray diffraction patterns. $CdS_{1-x}Se_{x}$ photoconductive films showed high photoconductivity after annealing at $550^{\circ}C$ for 30 minutes. And the films have been investigated the Hall effect, photocurrent spectra, sensitivity, maximum allowable power dissipation and response time.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1133-1136
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• 1999

A magnetic levitation control system is inherently nonlinear and very unstable. Thus there should be a stabilizing compensator network and a negative feedback path using noncontact photoresistor or ultrasonic sensors for the levitation operation. Since the photo sensor plays a key role in the system, the steady-state error and transient performance of the overall system depend on the characteristics of the sensors. But the sensor itself also suffers from nonlinearity, and the magnitude of sensor input heavily depends on environmental conditions. To improve the output performance, we added a linearizing circuit for the sensor characteristics and a disturbance cancelation circuit to avoid sensitive output due to extraneous interfering light.

• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.185-190
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• 2013

We report on direct finding of how the morphology (i.e. filopodia width) of $CD4^+$ T lymphocytes correlates with the size of the quartz nanohohole arrays (QNHAs, 140, 200, 270, and 550 nm in diameter) via scanning electron microscopy (SEM). This research exhibits that the filopodia of $CD4^+$ T-lymphocytes extended on the QNHA substrates were observed to increase in width by increasing the size of QNHA in diameter from 140 to 550 nm. This strong linear response ($R^2$=0.988, n = 6) in filopodia's width of surface-bound $CD4^+$ T-cells with topographical structures of QNHA can be explained by contact guidance between the cells and solid-state substrates. Furthermore, this research suggests that the protruded filopodia of surface-bound T-lymphocytes can be used as a biosensor for sensing the topographical information of the nano-patterned substrates.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.87-94
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• 1993

CdS and Se thin films were deposited on slide glass by EBE method respectively and surface morphology, crystal structure, electrical and optical properties were investigated by substrate temperature and annealing. The deposited CdS film was well fabricated with cubic structure at substrate temperature of $150^{\circ}C$. Se film was deposited with noncrystal structure until substrate temperature of $100^{\circ}C$, but Se film was grown with monoclinic structure at substrate temperature of $150^{\circ}C$. And so, after annealing at $150^{\circ}C$ for 15min, noncrystalline Se was proved to be hexagonal structure. Finally, the maximum output of Se/CdS heterojunction at 5000 lux was 4 $mW/cm^{2}$ and maximum spectral sensitivity was represented at 585nm.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.4
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• pp.341-347
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• 2013

This study presents the remote control of a board robot using a Sensing glove based on Bluetooth communication. The board robot is a kind of riding robot controlled by an user. The user wears the proposed remote glove controller, and changes a direction of the robot by different kinds of finger actions. Bluetooth is used for wireless communication between the board robot and its user. CdS cell Sensors and a LED in the glove are used for recognition of a number of finger actions, which are measured as analog signals. The finger actions have five commands ('1'right '2'neutrality '3'left '4'operation '5'stop), which are transmitted from the user to the board robot through Bluetooth communication. Experimental results show that proposed a Sensing glove can effectively control the board robot.