• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.10
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• pp.33-41
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• 2000

Pyroelectric characteristics such as voltage responsivity, noise equivalent power and detectivity are modeled 3-dimensionaly considering th interaction of each parameters. Also, the circuit is designed to set up the frequency band width and the signal amplification of the pyroelectric IR sensor. The case of low frequency region shows that the voltage response increases with the independence of the sensor area as the thickness decreases. In the high frequency region, it is found that the voltage response with the load resistor of 20$G{\Omega}$ increases with the independence of the sensor thickness as the sensor area decreases. In the low frequency region, the detectivity becomes excellent at th load resistor of 20$G{\Omega}$, the sensor area larger than $4{\times}10^{-10}m^2$ and the sensor thickness thinner than $1{\times}10^{-5}m$, while, in the high frequency region, it shows high value at the sensor thickness thinner than $1{\times}10^{-5}m$ and the sensor area smaller than $2{\times}10^{-10}m^2$ with the independence of the load resistor. In the circuit design, quasi-boot-strap circuit is employed, in which a single op-amp is connected to the drain of JFFT. Desirable frequency band width, amplification rate and the remarkable drop of noise of about 56% from that of conventional circuits with double op-amps are obtained.

• Journal of the Korean Magnetics Society
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• v.17 no.4
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• pp.156-161
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• 2007

To develop array magnetic sensors, specular-type giant magnetoresistive- spin valve (GMR-SV) film of Glass/Ta(5)MiFe(7)/IrMn(10)NiFe(5)/$O_2$/CoFe(5)/Cu(2.6)/CoFe(5)/$O_2$/NiFe(7)/Ta(5)(nm) was deposited by using a high-vacuum sputtering system. One of 15 way sensors in the area of $8{\times}8mm^2$ was Patterned a size of $20{\times}80{\mu}m^2$ in multilayer sample by Photo-lithography. All of 15 sensors with Cu electrodes were measured a uniform magnetic properties by 2-probe method. The highest magnetic sensitivity of MR and output voltage measured nearby an external magnetic field of 5 Oe were MS = 0.5%/Oe and ${\triangle}$V= 3.0 mV, respectively. An easy-axis of top-free layers of $CoFe/O_2/NiFe$ with shape anisotropy was perpendicular to one of bottom-pinned layers $IrMn/NiFe/O_2/CoFe$. When the sensing current increased from 1 mA to 10 mA, the output working voltage uniformly increased and the magnetic sensitivity was almost stable to use the nano-magnetic devices with good sensitive properties.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.308.1-308.1
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.33-34
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• 2012

• The Bulletin of The Korean Astronomical Society
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• v.30 no.2
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• pp.59.1-59.1
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• 2005

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.96.2-96
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• 2003

• Polymer(Korea)
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• v.32 no.2
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• pp.189-192
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• 2008

A styrylpyrylium salt (DHSP) was synthesized and then photodimerized to obtain a cyclobutane-type dimer (DHSP dimer). Methacryloyl group was incorporated into DHSP dimer to obtain DMSP dimer. Based on FT-IR analysis of a crosslinked DMSP dimer, it was considered that the cyclobutane structure reversed to styryl C=C bonds upon crack formation. Fluorescence measurement of DHSP in solid state (excitation at 385 nm) showed emission centered at 626 nm, while DHSP dimer revealed very weak emission. Fluorescent emission from microcracks in a film of crosslinked DMSP dimer was observed upon exposure to $330{\sim}385\;nm$ light.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.475-478
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• 2010

Fluorinated polymeric membranes were prepared by direct surface modification of PDMS with fluorine gas ($50{\sim}2000\;{\mu}mol/mol$ in nitrogen). The formed fluorinated polymeric membranes were characterized by FT-IR spectroscopy, GC (Gas chromatography), atomic force microscopy, and scanning electron microscopy. Direct fluorination resulted in the change of permeability and selectivity of various gases (pure gases such as $CO_2$, $O_2$, $N_2$, $C_2H_4$, mixture of He, Ne, Kr, Xe) through PDMS membranes. Fluorination resulted in the maximum 50% increase of selectivity through PDMS membrane.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.145-155
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• 2010

This paper presents a new approach to obstacle avoidance for mobile robot in unknown or partially unknown environments. The method combines two navigation subsystems: low level and high level. The low level subsystem takes part in the control of linear, angular velocities using a multivariable PI controller, and the nonlinear position control. The high level subsystem uses ultrasonic and IR sensors to detect the unknown obstacle include static and dynamic obstacle. This approach provides both obstacle avoidance and target-following behaviors and uses only the local information for decision making for the next action. Also, we propose a new algorithm for the identification and solution of the local minima situation during the robot's traversal using the set of fuzzy rules. The system has been successfully demonstrated by simulations and experiments.

• Journal of the Korea Computer Graphics Society
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• v.17 no.4
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• pp.1-10
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• 2011

The general technique of ink-and-wash drawing consists of brush, ink and paper modeling and brush movement, ink diffusion and paper material simulation. In this paper, we suggest the simplified Qing's tank model that can decrease the computational time of ink diffusion and absorption on korean paper. The suggested drawing system is classified the characteristics of ink-and-wash into ink-shade, diffusion, line and paper. Also, the user's movement using motion sensor and IR sensor in wiimote is transmitted to brush position and direction.