• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.42-48
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• 2000

Generally an operator would take notice at putting a patient under anesthesia. If the operation is executed in mistake, the patient is exposed to danger. The object of this Paper is that a system is developed for an accuracy of system and a convenience of user interface to prevent an operation of several elements of risk by mistake. The part of electrical system particularly is made for convenience of a manipulation using electrical switch and encoder. A real-time monitoring system is developed for an airway pressure and a gas concentration of carbon dioxide of patient using graphic LCD(liquid crystal display). Moreover, this flow control system could be developed control with accuracy by feedback control method. This is implemented using flow control valve and flow sensor. The implemented system gives convenience and precision of a manipulation of variable value using developed technique. This system shows guaranteed stabilization and confidence of anesthesia ventilator by notifying us that patient's state and information in case of being out of alarm range of variable value.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.10
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• pp.3334-3343
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• 1996

A quantitative flow visualization technique was developed to measure velocity and temperature fields simultaneously in a two-dimensional cross section of thermo-fluid flows. Thermochromic liquid crystal(TLC) particles are used as temperature sensor and velocity tracers. Illuminating a thermo-fluid flow with a thin sheet of white light, the reflected colors from the TLC particles in the flow were captured simultaneously by two CCD cameras; a 3-chip CCD color camera for temperature field measurement and a black and white CCD camera for velocity field measurement. Variations of temperature field were measured by using a HSI true color image processing system and TLC solution. The relationship between the hue values of TLC color image and real temperature was obtained and this calibration curve was used to measure the true temperature under the same camera and illumination condition. The velocity field was obtained by using a 2-frame PTV technique using the concept of match-probability to track true velocity vectors from two consecutive image frames. These two techniques were applied at the same time to the unsteady thermal-fluid flow in a Hele-Shaw cell to measure the temperature and velocity field simultaneously and some results are discussed.

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.258-264
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• 2003

The present paper studies how to calibrate hydrometer using image process. The method aligns particular scales of hydrometer selected for calibrating the hydrometer with the horizontal plane of the reference liquid automatically without man's operation. Major parts composing the system are CCD camera, frame grabber, stepping motor and image process program. The image process program is composed of a part that locates the meniscus and aligns it with a scale and a part that controls the step motor. To verify the performance of the developed method, this study compares the meniscus and scale observed directly with the naked eye with the result of calibration by the manual calibration method. The differences between the corrections were less than $0.004\;kg/m^3$ with uncertainty of $0.06\;kg/m^3$. These showed that the calibration results of the developed hydrometer calibration using image process nearly equal to manual method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1229-1235
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• 2014

At the LPG vehicle air intake system, most of dust particles in the air cleaner are removed. However very small particles are not removed and accumulated. The accumulation of carbon in air intake system is going to affect the idle speed control and sensor signal. It also causes engine chattering and transmission troubles of automatic transmission. This is study about cleaning up intake system using cleaning chemical. We can clean up the intake system by spraying cleaning liquid onto intake device when the engine is idling after intake hose is removed from warmed up vehicle. We can obtain the following experimental results by cleaning up ISC, surge tank, intake manifold, intake valves and combustion chamber. According to this results, the stroll valve works correctly and power rate of engine is up to the standard, it is smoothy to control the idling speed when a vehicle pulls up. After cleaning up CO grow down about 0.15%, HC does about 20~100 ppm.

• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.6-10
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• 2008

The amount of methanol crossover was measured with changing the operating condition by using a liquid methanol concentration sensor. Appropriate operating condition was discussed in terms of methanol crossover. Mechanism of methanol crossover was classified into three items which are diffusion, convection and electro-osmosis. Contribution of each mechanism to methanol crossover and the effect of operating condition were analyzed with varying methanol concentration, pressure difference between anode and cathode, current, temperature, and stoichiometry of anode fuel. Among the three mechanisms diffusion affected mostly and electro-osmosis effect was observed only under high methanol concentration.

• Journal of Biosystems Engineering
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• v.32 no.6
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• pp.440-447
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• 2007

In this study, a biosensor was developed using an enzyme-linked immunosorbent assay (ELISA) to rapidly measure the fungicide iprovalicarb residues in agricultural products. The biosensor was designed to include micro-pumps and solenoid valves for fluid transport, a spectrophotometer cuvet as a reaction chamber, a photodiode with a light-emitting diode for optical density measurement, and a control microcomputer to implement assay. The rate of change in optical density of the cuvet was read as final signal output. Micro-pumps were evaluated to investigate their delivery capability, the highest values of the error and the coefficient of variation were 4.3% and 4.6% respectively. As the incubation period was reduced from 15 minutes to 11 minutes to shorten the total processing time, the sensor sensitivity was decreased as the antibody dilution ratio was reduced to a half. The maximum usable period of the coated cuvet was found to be two days with 1% error limit. To predict the concentration of the iprovalicarb residue in agricultural products, a linear calibration model was obtained with r-square values of 0.992 for potato and 0.985 for onion. In validation test for the samples of potatoes and onions against the high performance liquid chromatography, very high correlation values were obtained as 0.996 and 0.993 respectively. Using the cuvet immobilized with antigen, it took 21-minutes for the biosensor to complete the measuring process of the iprovalicarb residues.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.191-192
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• 1998

We report on the design of a low-noise 40 channel SQUID system for biomagnetism. We used low-noise SQUID sensor with the pickup coil integrated on the same wafer as the SQUID. The SQUID electronics were simplified by increasing the voltage output of the SQUID. The SQUID insert was designed to have low thermal load, minimizing the liquid helium loss. The digital signal processing provides versatile analysis tools and the software is based on the object-oriented programming. For the effective localization of the source location, solutions of the inverse problems based on the lead-field and the simulated anneal ins were studied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.395-398
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• 2002

Many research group started study to develope x-ray detector using thin film transistor from 1970. But realization of TFT based x-ray detector development was caused by progress of thin film transistor liquid crystal display(TFTLCD) device technology in 1990. The main current of TFT technology is display device. Research results expend TFT technology field from display device to sensor manufacture technology. These days many research group in the world realize various digital x-ray detector. In this study, We compare discharge erasing method to visible light erasing method in a-Se based digital x-ray detector. Visible light erasing method is known reset process in direct conversion x-ray detector. Digital x-ray detector using visible light erasing method is not adaptive for conventional x-ray device, because of its thickness. And it is not avaliable for real-time imaging for digital fluoroscopy, because of its long reset time. In this study we overcome these limitations and show new idea for real-time imaging method.

• Journal of Sensor Science and Technology
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• v.13 no.6
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• pp.411-416
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• 2004

In the international temperature scale of 1990 (ITS-90), standard platinum resistance thermometer (SPRT) is a defining standard thermometer used in the temperature range from 13.8033 K to $961^{\circ}C$. Uncertainty of SPRT is about several mK and uncertainty of defining fixed points of the ITS-90 which is used for calibrating SPRT is about several tenth of mK. Above $0^{\circ}C$. the defining fixed points are gallium melting point and indium, tin, zinc, aluminium and silver freezing points which are all realized using an electric furnace or a liquid bath. To realize freezing point of tin ($231.928^{\circ}C$) and zinc ($419.527^{\cir}C$), two 3-zone furnaces which have 3 electric heaters were manufactured. Temperature gradient of the constructed furnaces were tested. Uncertainty caused by temperature gradient of furnace and immersion effect of SPRT in the sealed-type freezing point cells were evaluated 0.038 mK for tin freezing point and 0.036 mK for zinc freezing point.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.2
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• pp.90-94
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• 2016

In this work, [$Pb(Mg_{1/2}W_{1/2})_{0.03}(Ni_{1/3}Nb_{2/3})_x(Zr_{0.5}Ti_{0.5})_{0.97-x}O_3-BiFeO_3$] (x=0.02 to 0.12) composition ceramics were fabricated by the conventional soild state reaction method and their microstructure and piezoelectric properties were investigated according to PNN substitution. The addition of small amount of $BiFeO_3$, $Li_2CO_3$, and $CaCO_3$ were used in order to decrease the sintering temperature of the ceramics. The XRD (x-ray diffraction patterns) of all ceramics exhibited a perovskite structure. The sinterability of PMW-PNN-PZT-BF ceramics was remarkably improved using liquid phase sintering of $CaCO_3$, $Li_2CO_3$. However, it was identified from of the X-ray diffraction patterns that the secondary phase formed in grain boundaries decreased the piezoelectric properties. According to the substitution of PNN, the crystal structure of ceramics is transformed gradually from a tetragonal to rhombohedral phase. The x=0.10 mol PNN-substituted PMW-PNN-PZT-BF ceramics sintered at $920^{\circ}C$ showed the optimum values of piezoelectric constant($d_{33}$), piezoelectric figure of merit($d_{33{\cdot}}g_{33}$), planar piezoelectric coupling coefficient($k_p$) and density : $d_{33}=566$ [pC/N], $g_{33}=29.28[10^{-3}mV/N]$, $d_{33{\cdot}}g_{33}=16.57[pm^2/N]$, $k_p=0.61$, density=7.82 [$g/cm^3$], suitable for duplex ultrasonic sensor application.